I find that most of the MIDI-sounds coming out of the XV-5050 are very realistic, but of course some are better than others.
I have never found the time to fiddle around with improving the sounds. E.g. the flute, soprano- and alto sax sound great, but tenor- and baritone sax not so great.

There are probably some newer multitimbral units available by now.
Of course I am very much into jazz, so I prefer realistic instrument sounds and asked the forum a while back about soft synths, but I found the answers not satisfactory.

Also my guitar synth (GR-33) also has some sounds that are good and others sound like “toys”!

Real tracks are preferable in jazz and bossa nova, but in some commercial and latin styles, MIDI styles are better (I think).

I run BiaB from my HP laptop’s hard drive and have only USB2 ports.
I use only one into a powered multi USB hub mounted inside my rack.

The Fender Passport 150 PA system I use looks like a Samsonite suitcase, but unpacks into two speaker and one mixer/amp units. Each speaker unit contains 6 speakers, of which the larges four are 5” Ø.

So this is not "big" enough for the faithful reproduction of a bass, bass drum etc. That is why I use the 1 rack unit crossover filter, feeding a.o. in the two bass amps.

But a PA with larger speakers (or with one powerful bass speaker) will simplify your setup.

Hope this answers some of you questions!

Tonnie