lol, aww, you don't listen to the radio then? i don't see anything wrong with youtubing them a few times beforehand so you can know what you're buying. :) and yeah, their old stuff wasn't quite so dancey, but i love their overall upbeat feel! they're my feel-good music. a lot of my music is sad so i often need the dose! and lol, my favourite capsule song is obviously sugarless girl ;D though i'm a big fan of jumper as well!
if you like ayu and capsule, you might like utada hikaru! she released an english-language album that somewhat flopped ('exodus'), but i wouldn't really bother with that before her japanese stuff, though my favourite song on that album is 'let me give you my love'. in terms of english language, there are her fantastic OPs for kingdom hearts i&ii, 'simple and clean' and 'sanctuary'. she also has a wonderful song called 'beautiful world'. 'sakura drops' is fantastic too!