I can say they work very well in heavier vehicles, geared for 40-45mph. Higher motor speeds (within operating limits) coupled with lower gearing leads to less load, and less load means happier and potentially more efficient components. 6s is the way to go, no question about it.
With a lower kv motor its certainly raceable- 6s doesnt have top mean fast all the time. Only snag is 6s lipos are rather large, even the lower capacity ones to an extent..
You're right neil, your 120V wall outlet can power up a bunch of big washing machines + air conditioners..... it can just light up a tiny LED night lamp too.
The final output power is the factor, not the voltage.
I am sorry, but 6s on 2200kv motor is not a good idea for track.
If you are into brutal bashing with 100km jumps, than yes, if you want to go on track 2200kv + 6s is just wrong. packs are heavy and you have to gear down to 9-10t pinion.
I've been racing tekin 2000kv on 5s and it still has too much power on 14t pinion, had to go down to 12...
for racing on 2200kv motor I would buy 4s 5000packs, for bashing I will go with 5s and gear it somehow reasonably, if you want to run 2200kv + 6s anywhere near track, you will be dissapointed.