RE: NIMH VS. LIPO
I only just recently within the last 6 months converted all my RC's, accessories, and their radios to LiPo from NiCad to NIMH, and I am never going back, the advantage is clear, the thing I like the most is how light they are, I can gain performance in something on just the weight reduction alone.
As long as you don't do something silly with them they are extremely safe, I haven't had any problems yet.
I am 100% for lipo, no questions.