I don't think anyone believes Li-Ion lives forever, but in terms of memory and self discharge (particularly the latter) they are far superior
for my needs (sporadic use at a moments notice).
If you're using them daily, draining them before charging, have enough batteries (or a fast enough charger, although fast charging can shorten battery life) and enough self discipline (or a timer) to charge them "just in time" then I'd happily accept that there may be very little difference and there would be a major cost benefit of avoiding Li-Ion.
In my case, my old Ni-Cad and Ni-Mh batteries weren't holding a charge for more than a few minutes, so I felt I had 3 choices (other than not replacing them and using mains/hand power):
1/ Ni-Cad or Ni-Mh from a "good" manufacturer (+ve: option to buy Li-Ion batteries later if/when prices drop, -ve: memory and self discharge, particularly given my usage pattern)
2/ Li-Ion from a "good" manufacturer (-ve: price, which would limit the number of spare batteries I could afford)
3/ The Axion kit (-ve: build quality, possibly limited availability of spares, +ve price/bang for buck, 2 drills, 4 batteries in my kit, no memory or self discharge)
I chose what worked for me and have no regrets but, as with most things, other people can make a different decision and still be right
I've added a brief review of the Axion
here
