I own a DC-3, and have tried both the Mark I and the Mark IV. (I also own an F-50, and have owned a studio .22 (an awesome amp in its own right) and a .50 caliber plus).
For the money, you simply can NOT beat the DC-3, and at the very least you owe it to yourself to check one out if you possibly can.
Here's the comparison. The Mark IV is the flagship amp for your style of playing, there's no doubt about it. It wails, is infinitely tweakable (if that's your bag), and can handle whatever you need. It's got the graphic e.q, and if well maintained will hold value very well. That said, it's heavy as hell and is loud as hell. It's also expensive as hell. But in terms of performance, it's a world class amp.
The Mark I is NOT a channel switching amp. Both channels in isolation are awesome in terms of nailing the traditional Boogie tone. It is the archetypal no-nonsense boogie. But it has no e/q., and without the channel switching capabilities, it's not a highly versatile amp. Not too expensive if you get a used reissue. Also loud as hell, and you will definitely have heads turning with people wondering how the hell that tiny box is making so much noise.
THe DC-3 is a 35 watt 2-channel, channel switchable amp with the EQ. It's insanely versatile, sound INCREDIBLE at bedroom levels, and will even do the job in small to mid-sized rooms, and do the job without sounding like a small amp. Great clean channel, assignable e.q (which lets you engage in both clean or drive or overdrive only), and as much overdrive as you could possibly need if you are a blues and rock player. It runs on EL84's which have a special magic. The amp can sound like a Vox on steroids, or can nail the boogie wail no problem. Right now people are letting these amps go at ridiculously low prices sometimes. If you are a true tone junkie, you definitely owe it to yourself to try one of these amps out. If and when you do, just try playing this thing with cean channel master at 5 and the overall master at 5, and you will not believe it's only 35 watts. You won't be able to stand in the same room as the amp with the gain channel dialed in at those levels. But bring the overall master down to somewhere between 2 and 4, and you will really appreciate what this amp is cabable of doing. For the money, I don't think you'll find anything close. IT also has the direct out for recording and the speaker mute function which is cool. But with any of these amps, if you want to really capture the magic, you need to record it with a mic.
That's my opinion. Hope it helps. But please do yourself a favor and play test the DC-3. You won't regret it.
