I have gone back to zippy 8000 mAh lipos personally. The power I get from these are so much better than li-ion. Not quite as indestructable but I used to sag 50-80% of my 18650 12s4p battery pack at times. Now with high discharge lipos, I sag at most 15% on steep hills and less than 5% on moderate hills.
I’ll probably be the only guy here trying to convince you lipos are the way, but from real world experience, lipos not only sag less, but their discharge curve keeps the voltage higher for longer. This means you don’t slow down as much while late into your riding. It just drops off quicker near the end instead.
If performance is your top priority (as is mine), than lipos are the way to go. I personally think li-ion are not that much safer. Things can still happen in li-ion, look at boosted recalling their batteries due to venting with the A123 cells…