I would have to say the the lipo revolution just keeps looking better all the time. My customers are thrilled with running lipo's. I continue to see problems with the round cells (going bad, exploding, ect), but almost no issues with lipo what so ever. In fact I am the only one in this area (as far as I know) that has had any lipo issues.
I have had two of the Track Power packs swell badly and become un-usable. However, I do beleive that these were errors on my part as I have found myself accidently starting a charge using the wrong profile one more than one occasion. I hear that the pulses that come from some charge profiles can do significant permanent damage to a lipo in very short order.
All in all, I feel that lipos are the best thing to come along in quite some time. I recently got into 1/12th scale stuff and I am absolutely disgusted that I had to purchase more round cells.
Keep em crossed!