Is Bi - amping worth the trouble?

Well, in all honesty you might just be best off finding a more liquid sounding Preamp instead of neutral dark and punchy.. The bats are very good, but most of the stuff I listened to them with were on the more Damped sounding speakers like Dynaudio which mixed very well with the BAT tube sound... with the liver sounding speaker you have The VK 500 I don't think is your problem, maybe try a conrad johnson or Cary preamp with some tubey type tubes.. Mullards, Telefunken or something and see what happens. Then worry if bi-amping is a real need.

I'm with Undertow. I think bi-amping your existing system is basically "busy work". It will provide a change but you shouldn't look for an improvement commensurate with the trouble and expense required. After all, you really won't be changing anything. You will still have the same drivers, crossover, etc. The only thing you can achieve is more volume and you don't seem to need that.
Your money might be better spent on real change like a new listening chair.

Macrojack
that is funny. thanks. I have been giving a lot of thought to the chair lately. Just putting it off till I revamp the room. Making do with what's here, given the incredible prices of the furniture I have seen that I do like. You could get a nice amp for the price of the couch alone. so I've decided to settle for less costly a seating arragement. And rugs? My goodness!

For good or ill, my friend, this time next year ol' blindjim, is going to have two amps driving something. Probably be driving me nuts. A fella told me sometime back, as life improves, problems do not go away, all we can hope for is that the quality of them improves too.

I am also considering (passive) bi-amping B&W802Ds... Owning now two quite a big SS amps - Rotel RB-1090 and Parasound Halo A21, preamp Primare PRE30 (two pairs RCA output plus single pair XLR outputs), I wonder which configuration is appropriate: RB-1090 on woofer, while Halo A21 on mid/high terminals should be natural solution, given the power/watt capability (RB-1090 380Wpc, Halo A21 250Wpc). Some guys ephasized strong position of the "gain" factor of both power amps. I took a look at RB-1090 and Halo A21 specs, and not found any "gain" spec.

Guys, could anyone tell me something more about compatibility of RB-1090 and Halo A21 as pair of bi-amping SS powers?

BTW: I am building the new audio room these days, so not tested anything yet. B&W and Rotel brand new, received recently.

Zormi- Try to see bi-amping as a remedy. That is, something you apply in an attempt to overcome some shortcoming or failure in your system. You have brand new equipment ready to install in an unfinished room. Why not put it all together and see what you have before introducing change? You may not need or want to do anything at all.
Not all changes (mods) are improvements. And audio is not purely additive. More can be worse and less can be better.
Take your time and alter things gradually and, above all, one at a time. Fast changes make for slow progress and slow changes make for fast progress.
The only places where bi-amping is really useful are in powered speakers where the amps are onboard and dedicated to their assigned drivers OR in speaker systems specifically designed for use with an active crossover and multiple outboard amps. The rest of this stuff is just toyboy nonsense.