Yep, I agree. Runtime is shorter (3-4 hours?) but beam is a lot whiter. I like to add some diffusion film (satin scotch tape or something similar) to smooth out the beam a bit since it's a bit too spotty for a keychain light, but that is personal preference.
I would only do it if you alrady had a solitaire tho because I don't think it's worth the $ to buy it all new.
E0 is very similar to an Arc AAA CS, tho dimmer. Similar blue beam. Works well, just nasty tint.
12 hour runtime is hard to beat tho (alkaline too!).