Let me weigh in on this. I've got an HD500, a DT50-112, and a DT25 combo. I've been playing over 40 years, and have had a load of vintage Fenders, Marshalls, and a few boutique amps too.

To me the HD/DT combo is the closest I've ever come to perfection for a gigging setup. I just sold a Matchless, and have a vintage Pro Reverb for sale because the DT's have replaced them.

In terms of versatility, authenticity, and real tube amp "feel", this system gives me everything I need. The Fender's sparkle and bloom, the Vox's chime, and the Marshalls grind. I've got a Marshall JVM, and I like the Marshalls on the HD/DT's better.

I've tried the HD500 in a FRFR system, it sounded good, but I like my pant leg flapping from a guitar cab behind me. FRFR systems sound like a recording of my guitar tone to me. I'm in a band that rarely sends guitar, bass in keyboards in the PA, the venues aren't that big, so I need some stage volume. Plus, the direct out of the DT's sounds really good as a send to the PA, you don't need to mic the cab.

It's a great thing to tap one pedal, and change guitar, amp, and effects(I've got a JTV69 too). My band plays everything from blues/jazz to hard rock(with a bit of metal) so this is the only system that I've tried that can do it all and sound really good.

I've had few problems with any of the gear. Once, the memory dumped on the HD500 and I had to reflash the memory and recalibrate the internal pedal. This happened at home when connected to HD Edit. One venue gives me problems because I think the AC power drops too low and the HD has locked twice. I'm considering getting a power conditioner to solve this problem. Occasionally, I'll stomp on a switch to change patches, and the sound will drop out until I hit the pedal again. That's it for over a year of gigging and rehearsing.

As far as the DT50 vs DT25 is concerned, the 50 is very loud and sounds like a 2-12 cab. The oversize cab just has huge bass for a 1-12. The 25 is loud but smaller sounding, but not in a bad way, because the 50 can get a bit woofy. Because you can cut the power of either amp by going into Triode mode, I'd get the amp that provides the amound of clean headroom you need. If you're in a loud band with a hard hittimg drummer- get the 50. Otherwise, get the 25.

The bottom line for me, I've never been happier with my gig rig. I get compliments from my guitar playing buddies who come out to our gigs. More importantly, I'm happy with the sound, the feel, the easy of setup, and the consistency of tone.