Yes. You can make it sound good in the mix by illiminating all the abnoxious pan setings and getting rid of all the loud and useless reverbs. Some use of EQ is also required. I find that most Roland factory patches have a healthy range of lows and mids but they tend to lack in some hi-mids and therefore sound a bit hollow and "washed out". A compressor/limiter is also a big helper since it basically helps flatten the sound a bit (by this I mean illiminate redunndant dynamics liek sound going from extremly quiet to an annoyingly loud). Basically all of the above.

Most guys I know who use Roland workstations in their studios or live normally tweak up a few sounds of their own to fix all of the crap that Roland continuously keep putting into their factory sound sets.

-ED-