Paul Smith said in a recent video that the Dallas was designed to be a Super Reverb on steroids, and the Super Dallas is a super-Super Reverb on steroids. I agree with that; the Super Reverb is a 6L6 amp and to me the defining tone of a Deluxe is that 6V6 breakup. But I digress.
I have a DG30 as well. I have heard people say Vox, and I kind of scratch my head, because while it has a quartet of EL84Ms, to me it doesn't sound Vox except maybe at the very cleanest settings with the treble cranked up all the way. I'm hearing a lot of Tweed influence, maybe a bit of Magnatone, a bit go Gibson GA series, but mostly it sounds unique. I have one of the "first 20" with the BRIMAR NOS preamp tubes (one of which is going bad, I'm swapping that out today, and yes if you can find a 60s NOS BRIMAR they do go for $100 a pop!).
I'm quoting from Doug Sewell's PRS sheet on the amp about the difference between the 50 and 30:
"This amp {he is referring to the 50} was designed to be a bit more straightforward and scaled down.The circuit, tubes, and voicing are less prone to need the extra tweaking with this amp as it was not designed as a larger scaled clone of the 30. The master volume is located in the circuit differentlythan on the 30. It is a post-phase-inverter master and allows for a touch more independence of thepreamp distortion to the power amp distortion. In other words, the player can dial in preamp distortion with the volume control and the overall volume can be dialed down with the master without affecting the gain as much."
In any case, it's not like a Dallas.
Like Aristotle, I haven't heard a 50 Watt version live, but the 30 and 50 have differences in how the Master volume works according to the sheet I got from PRS about the two amps. I can't speak to the preamp sections.
The 30 is a very, very versatile amp, though fair warning, it's a big boy amp in the sense that it sounds best pretty loud. It takes pedals extremely well if you're into that, and distorts in a unique way that almost puts a "halo" of grit around a note, yet the note itself shines clearly almost as though it isn't distorted. It's hard to explain, but it's a cool thing.
Also expect to take some time learning its ins and outs. The amp is a tweaker's delight, but at first you may be puzzled about it. My suggestion is to start with the Master up around 2 o'clock, and then dial in the gain, etc. That'll give you an idea of what the amp's range is, you'll get what's happening, and then start adjusting from there in terms of finding the right MV setting.
The boost control on the rear panel almost makes it a different amp. About halfway on the gain control (the preamp gain) the amp changes character noticeably, and there is a volume "push". All this stuff gives you a very wide range of tones, and makes the amp a wonderful thing to play - and play around with!
Also the DG cab isn't just a matching cab in terms of looks. It's really an important adjunct to the tone of the amp by virtue of its pine construction, porting, etc. In fact, the DG cab isn't a "do-all" kind of thing, it's really not a cab that works with every amp, and that tells me that the two go hand in hand. My DG30 sounds much better with it, so factor that into the equation.