Actually, the Express 5:50 is the next amp that I'm going to buy because of its clean tone. I tried it out a few times compared to some other amps (Lonestar Classic, Lonestar Special, Fender HotRod Deluxe, Fender Blues Deluxe, etc). There was just something about the Express that really impressed me. It had a very rich clean tone that wasn't too thick like the LSC was, and wasn't as laid back as the HotRod Deluxe was. Overall, I was incredibly impressed with it. Plus, I really like the verb on it, especially for doing some "cowboy guitar" tunes.
NOT liking the "Burn" setting on channel two though. There's something kind of ratty sounding about it. It's fine when set to Blues, but it doesn't seem to do high gain well. That's ok though, I'm going to get collection of pedals and run them into the clean channel (I used to have more than I do now, so I have to invest in some more again). I have a cool FX loop pedal that I had a friend design for me. Basically, it has two FX loops in it: A and B. There are three buttons: A/B, A into B, and bypass. I use it like a clean/dirty channel switch on an amp. I have all of my distortions in one loop, all my verbs, delays, and other things that I would normally use on a clean tone in the other loop. That way I can switch between a dry distorted tone, an effected clean tone, an effected distorted tone, or a dry clean tone. It's' actually quite a handy little unit. I came up with the idea because of how I have my Mark IV set up, which is that the FX loop is always engaged when I'm on channel 1, and is disengaged when I switch to channels 2 and three, but I can turn the loop on via the footswitch on channels 2 and 3 should I have the desire to. I thought "wouldn't it be great to have a pedal that would do this for me for my practice rig (I run a Mesa V-Twin and a Line6 M13 into a little Marshall Lead 15 stack). At the time I came up with the idea, the external loop on the M13 was not assignable to a certain scene and could not be turned on and off. So, I needed a way to be able to switch back and forth between a dry distorted channel and an effected clean. That's when I came up with the idea for the pedal. Ordered the parts for it, built it up, and now it's up and functioning just like I wanted it to. Doesn't get any better than that.
Next thing to do on it though is get the LEDs figured out. Haven't quite decided the best way to power them yet though...