I think that would be the case, but just a suspicion...

I think that the C rate is still useful info, but I also thing that varying the C rate to a constant LVC and maximum temp would show the ultimate durability and performance of the cell.

I also think that using pack that is assembled should be manditory. I've been pondering how the tabs have been failing on some brand name lipo's during use, but the manufacturer has obveously tested them at huge amp numbers. The problem I believe is external to the cell, it's related to the method of assembly. Specifically the manufacturer is spot welding the tabs and them folding them over. I'm confident that the pack no longer has the ability to perform to the specs that the individual cell had.

I think assembly methods could even cause localized heating at the tabs of the cell, causing heat damage while the rest of the cell is at an acceptable temp.

That seems to have been the case for the trakpower bricks. It seems that the current 25c packs are the same as the previous 20c packs that were just conservatively rated.

I must admit that I would prefer to buy packs that have been rated conservatively over the alternatives...

I agree that their seems to be no "standard" for providing the individual cell and/or pack ratings on Lipos - one manufacturer's "20c" pack is another's "15c" pack, and without reliable test equipment and a controlled environment, the information is somewhat useless and speculative - purchase decisions must be made largely based on whether or not the customer "believes" the ratings posted by the pack manufacturer - based on other's opinions and experience I guess.
I test my batteries in actual use with an Eagle tree data logger - before anyone asks, I don't plan to post graphs, but rather I use the information to make recommendations to customers who ask - I do take the job seriously when someone has a particular application and is seeking advice on a "safe" setup, and a 12c pack in the right capacity and application is often times a better choice for the consumer than a 25c pack with less capacity - ultimately depends on the customer's end goal.

I test everything in the same manner - starting with a fully charged pack at ambient temperature and discharging it in harsh use until it trips the LVC. I then scroll through the data to see pack voltage at given amp draw throughout the run(10 frames/second). I also test multiple cells/packs in any given session - same day, same temps, same conditions - this way I am "apples to apples" as much as possible.
In RC Cars and trucks, burst rate capacity is more important than constant discharge rate IMO - the average draw of any given run is typically below 30 amps, but I see spikes beyond 180 amps throughout the run. 100 amps continuos draw would yield a 3 minute runtime at 100% through-put with a 5000mah pack - this just ain't gonna happen, and is therefore fairly useless IMO.
I make by judgements based on whether or not the pack can maintain 3volts/cell throughout the run. Constant discharge rate isn't important(or possible to record with my method), so long as the pack can maintain 3 volts/cell throughout the run - at least this is my opinion. If it can't, then the pack isn't suggested for the application, regardless of its posted specs.
I have tested packs from every brand listed on my site(and then some), though I have not tested every individual pack. PolyQuest, Flightpower and NeuEnergy packs all have handled beyond their stated burst rates(at least up to 175 amps, which the most I can accurately measure - special praise to the PQ2500 packs, which maintain 3volts/cells up to about 70c!!). I have some other cells "in testing" that have exceeded the above packs significantly as well, but long term testing is still under way.
Anyway, these are my thoughts - until a standardized and non-biased test system comes into play, the only info I trust is what I can prove in actual use. :)

I like real world testing as well. But for the companies that do sell cells/packs, they should have the testing others and I mentioned to see how well they do with different C ratings. If the cell/pack states a burst of 50C then do a 50C burst to see what the cell/pack can handle. Like Mike mentioned about the average AMP, now that would be something a company can do as well. Try and get results on a constant discharge of various AMP rating. Get a constant 10A, 20A, 30A and so forth. That way we can see how well the pack can hold at those ratings. I have seen spikes of over 180A, but my highest average so far has been the most 35A. I also like how my 2200mAh packs can handle spikes of 180A+ and still provide plenty of juice for a 15-20 minute run. This is not race conditions.

Have you guys seen this before?

It appears to be a step in the right direction.

It sure is a step in the right direction. All they need to do now is have repeat tests and find out how many cycles it take for the battery to start loosing power. The only problem is it'll take a long time and lipo cells are getting better.

Those may be Common Sense ratings and perhaps their batteries too.

A little bump for new discussion.

John, more than C ratings, I'd like to see some SIZE standards. As a pure basher I have no real need for insane discharge abilities, but it has been quite irritating to be limited on pack dimensions. Seems like many of the better performing packs were designed for RC aircraft, which are more adaptable to the available space. Even the cheapo Rhino 2S 4900's, which I would love to try-are too long for my application. I see Hyperion is the first to address this with their Swift 4000 packs, those are 20C rated (and I would trust Hyperion to be honest with that) which is fine for what I want to do. Hopefully the the others will follow suit.

On the topic of physical size: It would be nice to know the exact dimensions of the packs. I've seen a couple of times where the pack is spec'd at X mm, but when they arrive, they are actually X+2 mm. I understand the end where the connections are can vary somewhat, but at the very least, round UP. I would much rather add a thin piece of foam to make them fit right than to rebuild (or re-order) a new tray.

I had that happen with some packs recently. Ordered the Elite packs, had Mike make a tray, and the pack was about 3mm wider than stated.

In my case, it was the end where the connections are. Like I said, that can be accepted I suppose, but to be off on the width?? Did they use extra thick heatshrink or something? That is unacceptable, especially that much; 3mm is just about 1/8"!

Of course all packs can't be measured, but come on! Just measure the largest one, and add 1 or 2 mm just to be safe.

Funny you should mention Elite, I just got my 3s 3300mAh packs in today. They are advertised as being 135 X 45 X 19.5. They measure at 140 X 48 X 22. Hmm, that's quite a bit off! Luckily my tray will allow this discrepancy! Then again, these were supposed to be 30C cells, but the packs I got say 35C. They don't have 35C 3300mAh cells on their site, so these are either new versions, or they just bumped the rating...

As a calibrator (someone who measures things, like voltages, for a living to test for accuracy and consistency) I really like the sound of that. Precise, consistent, and most importantly, repeatable.

@FireWire79: A little off topic, but can you calibrate a multimeter? I have a Fluke 97 that needs to be calibrated as it's been a few years.

I then use this calibrated meter to in turn calibrate my other cheaper meters. Not perfect, but better than nothing.