I got used to the feel, but I never got to where I really liked the feel. I do a lot of sliding and a little tapping and neither work well with the rubber strings. I'm keeping it in case I have problems with my wrist again (that was why I bought one, I'd reached the point where problems with my wrist were severely limiting what I could do on the bass). The biggest down side for the UBASS for me though was the complete lack of sustain. Even compressing the bejabbers out of it I just couldn't get any sustain. Them big ole' rubber strings stop vibrating pretty quickly no matter how hard you tug on 'em and when they stop vibrating all the compression in the world doesn't help.
I'm keeping it in case I have another bout with my wrist, and for when I need to do something really bouncy and complex that might aggravate my wrist if I tried it on the five-string, but it doesn't get much use now.
John