Biamping with sonically different amps usually doesn't sound as good as you would think. Even with the same kind of amps the advantage of biamping has more to do with improved power delivery compared to a lower powered amp that struggles with the bass and audible distortion heard in the top section. Your 250s have plenty of power so technically, imo, you don't need to biamp and it will sound better with one amp full range.
Jumpers can have a huge effect on the sound and people can mistake "biamping advantage" when they also got rid of the stock jumpers with better speaker cables. So make sure jumpers are not holding you back. OEM jumpers often not as good as the rest of the speaker. Must be pure copper or better. Also experiment with speaker cable connections: +/- both on bass, both on top, or split top and bottom both ways. It really does make a difference, even with excellent jumpers.
