I've just got a B3 now discontinued.I've been using the Mb60 stomp box live until now.I love the software editing of patches and the ability to download and save ,Usb connection to my mac allows recording directly to my DAW(Garage Band) essentially an audio interface.You have to really plan your banks of fx as only 3 are available at any given time but with a little thought this Isn't a problem..I've found it to be little noisy especially the compressors but if you lower their gain then that's sorted.
Its uses for me are
1) Playing the upright live.The b3 can give you more control over your sound be it compression, pre amp, cab sim or eq( it will never replace a good set of mics but we all know the problem of miking up an upright in a live situation. Tc have a chorus effect called "The widener" does what it says on the tin and fantastic for spreading the upright sound around the stereo spectrum. I've recreated this with the ensemble effect, which is really neat for the upright
2) Enhancing the fretless.It's been a good send in this dept.The Bass now has a unique voice well Jaco really but without the chops..
I could go on. Iv'e set a patch for the Jazz bass based on Marcus sound and the P Bass sounds like it's come straight out of detroit well circa 1965.
In conclusion
I've never really had a great studio sound as most engineers understandably can't read your mind when you have a sonic idea in your head.With the B3 I can now rock up and have several options at my finger tips unfortunately with studios closing down and Digital recording available to all I can't see this happening soon. Great piece of gear though...