Well I love using my 360 controller for games like DMC, Racing Games, Soccer, etc etc. but anything that requires aiming I simply can't play with sticks.
It's also not a matter of getting used to it... I own a 360 since sometime 2007 and I tried playing Halo 3 countless times and also Gears of War etc. everytime it ended with my hands cramping together and me not hitting a 2km² large wall from 1m away.... I love AC4A but to be honest it's a miracle that I even finished it once.... I had to use lame tactics and had a crapload of luck, there was never any sign of fluid gameplay. Okay maybe when I escaped the AF Great Wall but I wasn't really fighting there^^'

If I could play AC4A/AC5 with a Mouse and Keyboard, believe me I would pilot my NEXT like it was my own body.