I havent heard the Burson DAC nor the W4S DAC, so I can't comment on if the Rega DAC is better or not. Neither are available locally to me, and I'm not big on Internet direct brands, especially when W4S doesn't offer 100% money-back if you return it. I'm a bit too particular in what I'm looking for and too frugal to get involved with shipping stuff back and forth. Add to that that I've got a great local Rega guy, and my decision to audition the Rega DAC was a no-brainer. With all that being said, a bit of insight on the Rega vs Bryston BDA-1...
I've owned the Rega since the first shipment to the US (serial # 25 I believe). I've heard the BDA-1 many times, and own a Bryston B60, so I'm obviously a Bryston fan.
The BDA-1 and Rega are different animals. They're similar in some ways, but different. The BDA-1 is more detailed, open and airy sounding. It has a larger and perhaps closer and more intimate soundstage, and images are truer in life-like proportions. Bass is a bit lower and more controlled. It's a better DAC in every hifi sense. The Rega doesn't do a single hifi thing better IMO. The BDA-1 isn't all hifi and no music though. It's extremely musical to my ears. Music glows with ease and poise.
The Rega seems a bit more closed in and distant sounding. Not in a bad way, nor in a laid back way; the soundstage is smaller and a bit further back.
The Rega DAC's truest and best strength is that it just makes sense of the music and gets it right. Very hard to explain. Listening to Hendrix's Little Wing made me get this very quickly. That track is a mess with every other source I've heard it on. One of my favorite songs, yet I can't listen to it more than once an hour or so. Until I brought home the Rega anyway. The first night I had the DAC, I played that song 3 times in a row. The third time was to make sure I wasn't imagining that my purchase was justified.
Another track that made me appreciate the Rega was Metallica's Orion. It's an instrumental track with 2 bass solos in it. I always knew which solos were the bass solos, but they never sounded like bass guitar to me. With the Rega, they became obvious.
These things weren't due to increased detail or anything like that. The only way I can describe it is to say the Rega just makes sense out of music. It may sound like a cop out on my part, but it's not.
The BDA-1 is a better DAC. When taking price into account, you have to factor in features like connectivity, sample rate flexibility, etc. This adds to the cost and doesn't keep the two on exactly even ground.
Had money not been an issue, I'd have brought home the BDA-1 and Rega DAC and compared them directly. Not sure if the BDA-1 would have done what the Rega is doing though.
I hate the analog analogy, as I think it's used way too often. However, the Rega sounds like a great turntable. Not a smoothed over, warm, lush and slow turntable, but a great turntable that gets the heart and emotion out of the grooves and into your room.
If you're looking for new details in your music and/listening to bits and pieces of your music rather than the overall picture, you won't get what the fuss over the Rega is all about. If you're sitting back and experiencing a complete performance, the Rega DAC should make itself very well known (in a good way, not a 'listening to the component' way).
The BDA-1 is a more polished and proper sounding DAC. Not sure if it gets the music as right as the Rega DAC does. I'd love to hear them both in my home, side by side for a few days.
Also keep system synergy in mind. A friend with trusted ears didn't have the same experience with it as I did. He heard what I heard, but in his system (I think his speakers moreso than electronics) the Rega was reportedly overly warm and bass boomed a bit too much for his ears. He has an Exposure integrated and was running older Castle speakers if I'm correct.
Synergy will make or break a system IMO.
Also...
Even though the W4S DACs are pretty much universally praised here, there are people who didn't like it. Another trusted friend found it a bit too dark sounding. He wanted to keep it, but after a while he grew tired of it. Again, synergy will make or break a system. I've heard the dark sounding criticism of it from a few others, but I don't know them to be able to tell their preferences.