flatback said:
I am really curious about how a FC thru U5 and Bergatano 112 or pub 280 sounds.
Funny you should ask. My brother, who wins my Tom Bowlus runner-up award for gear warehouser, loaned me his U5 and REDDI, which I have been playing, mostly through my Pub. Both front ends sound awesome!
(Too bad bro doesn't have a Summit.

)
The REDDI, though it sounds fine--maybe even a little better to me (warmer and deeper) than the U5 even, is not rated as a high impedance that you'd normally want to load a piezo, though, and also it doesn't fit on top of the Pub so well. Also it costs more and doesn't have all the flexibility of the U5.
The U5, OTOH, fits perfectly on the Pub and it sounds killer good. I think I like tone curve 1 best, though 3 & 4 would also be appropriate. I might end up buying this unit, though this small compact rig that looks like it was made as a set is not at all what I would call portable, at least not given its ~60lbs total!
I did some comparison to my LDS and Clarus, but not much, and I've not yet tried the U5 (or REDDI) as a front end for the Clarus as power amp. The LDS/Clarus combo was more hollow, without the punch, warmth, and full fidelity of the U5/Pub. Though I didn't take a lot of time to adjust the Clarus tone controls either. This is still a trial in progress.
I also should note that a friend built up one of the Altoid box buffers, and I also tried it between the FC and the REDDI and this sound was to die for, even with no tone adjustment. I still think I could be totally happy with the much more feature-rich U5, though. (I didn't even try it w/ the buffer because the U5 input Z is already 3M ohm.)