James Tanner, big cheese at Bryston, is quoted on the Bryston AudioCircle forum that the BDA-2 and BDA-3 sound identical except for the additional connectivity options on the 3. Some owners said he was wrong. I will go with Tanners judgement on this.
I just bought a used Bryston BHA-1 headphone amp and 2 channel preamp (after some factory mods). I was looking to get a BDA-2 to pair with it, but decided to use the 2 inputs on the preamp to connect a Tuner and SACD player. So the BDA-2 would not have an input to connect to. I had zero interest in the BDA3 after Tanners comments. I will get a used BDA-2 if on the off chance the Tuner and SACD player don't satisfy (doubtful)