I have used SD5, Midjay, and now Audya with both big and compact Bose systems. Love the sound I get. I've also used it (and still do some) with Roland E80 and 50 with equally good results.
What the Bose does is let you hear what you really sound like. If you aren't ready for the truth you may want to use something that hides stuff.
I generally use an external mixer (currently the Edirol), but almost everything is set flat. The Audya comes out of the box sounding great and doesn't require much e.q. adjustment. I do use the dedicated Vocal e.q and effects from the Audya to help my voice sound more like something I would want to listen to.
I tried Semilive's 330 and it is surprisingly better than one would think, but to mention it in the same sentence as Bose seems ridiculous to me. However, to each his own. If it makes you happy and your audience doesn't care, go for it!
DonM