The last thing I would gainsay is that the DR is one of the ultimate small club amps as well as among the most recorded amps ever.
This being said, a couple of considerations.
The first is that Dead playing requires more clean volume and headroom on tap than many other genres.
The second is that many people feel DRs don't provide them with enough of either.
Don't take my word on it. Check out almost any guitar forum. You'll find frequent threads asking how can I get more clean volume and headroom from my DR. Suggestions will range from swapping out the 6V6s for 6L6s and rebiasing, upgrading to a more efficient speaker, replacing the tube rectifier with a SS plug in (don't try this on a vintage DR without first upgrading your filter caps unless you want to also lose a transformer), and upgrading the transformers. Those steps can not only get expensive but may still fall short of the amps' users' needs.
My personal recommendation to folks in this situation is to consider instead what I deem the most effective "mod": replace your DR with a VR (if anyone can find a thread where someone is asking how to get more clean volume and headroom from his VR, point it out to me - I can't recall one).
Bottom line: DRs are beloved for sound [double entendre intended!] reasons. One may work perfectly for you given your needs. Just be sure you mean it before you start plowing money and mods into yours chasing the more clean volume and headroom dragon.
But if you're set on upgrading your DR: http://acruhl.freeshell.org/mga/main/deluxemod.html