stuck with 4s, What C and mah ratings you run ?

[RC-Monster Mike]

The G3 Hyperion packs are hands down better than Losi or SMC packs. Maybe NO one you know runs the G3 hyperions, but it is rather unlikely that these folks have near the experience and knowledge of the folks that hang out here. Not everyone here runs the Hyperions, but anyone that does knows the deal with them.
The problem with most hard packs is that the cells aren't atached to the case, so they actually bang around slightly inside, where a soft case pack can be attached directly via the straps used to hold it. Also, you may not see a issue that develops with a hard case pack(because the pack itself is hidden inside the hard case).
In the end, its your money, your car and your decision. I have been around the block a few times and can only tell you what my thoughts are. The fact that the locals in your area aren't running them only indicates that they either don't know any better(likely), are perhaps sponsored in some way and run the packs provided, or simply bought what they saw an advertisement for. If you can get away without using a hard case battery, I would suggest it. The Hyperion G3 packs specifically. :)