In the beginning I was just really into using Anki for whatever I could :P So I studied pretty much everything in there, but later on I started using pen and paper much more. To be honest I wish I spent more time away from Anki, especially in the beginning, because I had a hard time managing reviews after awhile. But there's still something about adding cards and seeing my decks get bigger that can keep me coming back more than pen and paper can.
Yeah I agree that learning X number of kanji isn't a useful metric. I found it really helpful getting exposed to a lot of them in the beginning though because it helped me build up my mental model and start to recognize them as groups of radicals instead of a bunch of random lines. I know what you're saying though -- I tended to (and still tend to) focus a little too much on numbers, and if I put more time into focusing on building up certain gaps in my knowledge that need to be filled I'd probably be at a higher level right now.
Thanks for the comment! Always fun talking about Japanese learning methods :P