The wavetables help a lot, I guess - even in their VA they can be found as an extra. Those aren't available in any other synthesizer. It can give the proverbial silver lining to the cloud - transcend basic analog sounds :).

Here's what happens in detail:
http://www.synerjee.net/crap/qtables.mp3

It works better if you hear it in 'normal use'
http://www.synerjee.net/crap/qtable2.mp3

Examples are from the Q rack.

The pure VA sound itself could be compared with RGC Z3ta+ in my never so humble opinion. It's just as 'bold' and bright.

I don't know about the XT but it's got that same Waldorf-taste; and you can do much more exciting stuff with the wavetables and filters, mainly because you can build your own.

It differs from the Virus' spectral waves in the sense that you can modulate it without stepping, which allows slow evolving sounds. For the record, I've got both the Q rack and the Virus C.

For hardware support : I've got the one-before-the-latest OS on my Q (3.00). Arpeggiator doesn't always match (I don't care), but it has never hung up on me. It's built well; the only trouble is that the new partially translucent potmeters (Alps) aren't in production anymore IIRC.

The XT has the 'mono clicking bug' which has been the mote in the eye for a lot of people on the mailinglist.

The company that has taken over some of the Waldorf stuff is http://www.stadler-electro.de/

They haven't updated their frontpage for a long time, so I don't know what the word on that is. Also, the OS development for the Q and the XT is frozen; it has to be bought back in order to be developed further (again IIRC).

The complete contents of the FTP (soundsets & stuff) can be found here : http://waldorf.electro-music.com/ . http://www.waldorf.synth.net/ has a backup of the old site. I have no idea if the mailinglist still works; I was unsubscribed and didn't bother to get back again.

I've got a Microwave XT and the build quality is really good IMO, all the knobs work as they should and filter sweeps are very satisfying.

I use it in Cubase and can open up Soundiver alongside this which enables you to constuct your own wavetables. You can select from 500 waves or from ones you've drawn yourself and jiggle them around - transmit them to your machine and instantly play the new wavetable.

I had a Waldorf Q rack before this but like the XT more because it's so much more easy to use with all the extra knobs.

The thing about the XT is you can get from a dirty electronic stab to a floaty pad in just a few tweeks.

It's more of an an extra to an existing setup and isn't the best choice if you're after a mainstay synth for your setup.