Battery life was my big reason for gravitating towards devices I could replace the batteries in like my Vamos, mechanical mods, rDNA40s, Sigelies, etc. But for the price, and massive capacity, I had a hard time passing up on Innokin's MVP products and have an MVP 2.0 which months ago was a fantastic purchase but today massively overshadowed by the newer MVP 3.
If the battery can't be replaced, I can't think of anything outside the MVP from Innokin that I'd consider.