Surely it wont be long before Lipo battery prices come down to a reasonable level and our batteries then weigh about 1.5Kg 
You forgot to say ''.... and deliver 100 Ah + 1000 CCA''. 
I use Lipos in my RC planes (My job is selling RC toys LOL), have a 5000mah 11.1v in 2 of them and they draw 100A peak current anyway, Lipos are based on C rating, so you get 5A battery with 20C means it can offer 100A peak current, likewise a 5A 30c battery can give 150A if needed, although my own models tend to only draw 85A max on full throttle (That electric plane does around 140mph top whack

).
Larger planes you just put them in parallel or series to bulk up amp and mah capability, still they weight not a lot anyway, not compared to PB batts.
IM sire in years to come tyhey will be in cars, my golf trolley is also LIPO powewred now.