I use a DRRI and I've modded it quite a bit, mainly because I love to work on amps. I've replaced both the stock output and power transformers with Allen transformers and I run it with 6L6 tubes instead of 6V6. These two mods turn it into something closer to a 35 watt amp vs. the stock 22 watts. I also run it with a plug-in solid state rectifier and a Jensen Neo 12-100 speaker. Finally, I've modded it so that both channels have reverb and tremolo and I have also added a switch on the back to disconnect the tremolo which adds gain.
I love it...a great little portable, versatile amp with some serious oomph when it needs it. I know some may question why I didn't just buy a different amp. Again, part of it was just the fun (for me) of tinkering with a amps. But also, I'd say that for what I now have in terms of versatility & portability, the amp is somewhat unique. YMMV.