I just picked one up this week. I really like it. I did my homework when shopping for an amp. For me, in this class/price range, the Tour 450 wins hands down. I am playing it through a Carvin 1x15 600W 8ohm cabinet, and I really enjoy the headroom. For a solid state amp, it sounds relatively warm and round. If crunch is your thing, you will not be disappointed.
Disadvantages: It does not come with a foot switch. I really believe that amps should come with all the "peripherals" needed to fully utilize the amp. It is a mono switch ($25 at your local shop) and it controls the amps octivizer. This is not something I am in hurry to buy because I don't really use the effect that much. However, I wish the footswitch worked with the EQ defeat or even the mute switch (handy feature!) on the amp.
Keep in mind that I believe that most solid state amps in this price range sound pretty much the same. However, Peavey has a reputation for building bulletproof gear. Also the Tour series has a bunch of USEFUL features for the average bass guy... like me.
I am going to post a review of this amp as soon as I gig it.... or play it in rehearsal a few times.
Original Poster: If you have any questions about the amp, feel free to PM me. I am happy to help in anyway I can. A bunch of guys and gals here on TB helped to educate me on amplifiers and cabinets. I want to pay it forward.
GB