Well! Where do I start....... I had the chance to test drive a WD-800 @ my local Guitar Showcase in San Jose this afternoon. And all I can say is wow. I purposly tried it out intially with headphones on. Why? I don't know, but perhaps just because I could. And it was beautiful. I was tonally rich and colorful and sounded great with the phones on..... Then, I plugged in the the SW 1x15 & 2x10's. first thing I'm am going to say....... VERSITILE! You can dial a wide range of tones to work for your particular bass, for your particular sound. That being said, I can say it DID have the flavor and pedigree of my beloved M-Pulse 360. Why do I love my M-pulse so much? Well, to my ear it had that touch of HiFi that drew me away from SWR, mixed with a little rumble of an SVT, along the Mesa M-Pulse sound. Most of all, my M-pulse is VERSITILE, so friendly with anything you put in front of it. Did not take long to dial in the sound I liked. The learning curve was quick as it layed out similar to the MP. The Hi Pass filter is the $h!t. That right there, IMO will be 30-50% of the tone/sound you are looking for. I liked the HPF in fully counter clockwise range for my tastes. I saw something at the corner of my eye......... and the stars alligned, there was a Walkabout Scout sitting in the corner on consignment! A/B time!!!!!! I plugged in and did my best to adjust the same settings between the two, there is a frequency shift between them on the para eq dials.....and I got them pretty darn close. What can I say, Andy did one hell of a job making the WD sound so much like the original! IDK, 80-90% there? Well pretty darn close to make anyone who loves the WB sound to go out and the WD. The WD-800 was tonally, very round, rich, and colorful. The harmonics and overtones were like a rainbow that you can see, taste and feel. Very tubey, a step up from my already, very tubey MP. I loved the tube break up after 2 Oclock, infact I loved it more with the gain turned all the way up! Guys and gals, you should have little to no issues with clean headroom at high volumes with this one! I didn't go past 9:30 or so on the volume in the store. Volume? Well I wondered if 800W is simply too much for me to play through my PH 4x12, as my my MP 360 is plenty loud playing with two 100W half stack playing metal. Another reason as far as too much is that, how will it sound at bedroom volumes? Well, the volume is VERY linear compared to the MP line. That being said, you will be able to enjoy this head at home at very low volume. Just like my MP and the Walkabout, there is that very tiny thin line where the volume shoots up exponentially compared to the WD. I would bet they tested this head with the older Powerhouse cabs in mind, along with the SW series (Andy?)..... So I have no doubt that this will sound GLORIOUS through tyhe PH line. The only thing I don't have an opinion on is the dampening switch, I'm sure because I was in a store, in such a controlled enviroment, that i really couldn't let loose to give it a fair shake. I used my EB Stingray, Slo Special Stealth for todays demo. Andy? I don't know how much of it was my bass, but this amp really made me feel like I was plugged into my MP...... but it just had a little bit more color,tube gain, and fatness....... it was GLORIOUS! How much of the M-Pulse DNA is in the WD pre amp? I did notice there are mosfets in the power section of the WD. I hope my review is helpful to you guys and FYI, the SN # on this bad boy was #93. They are sold out at this store besides the floor model, and I was told that four more are coming in next week before Christmas in case anyone in the Bay Area wants one of these now. Will I sell my MP360? No! Will I get the WD-800...... Yes!, just not now. I'm a gear hoarder and I need to purge some of that first.