Hey man, I don't actually use a DI, I just send a signal to the board out the back of my SWR SM900 however I do use a Radial Bassbone, it's awesome. The reason I bought the bassbone is because I use 2 basses and I needed a better switch then the Morley switch that I've been using for a few years. The Bone was a little more then what I needed as I don't really need a DI but it does have an FX loop which I needed and the channels have an EQ which I was okay with but I thought it might be a bit noisy. When I took it home and pluged it in I thought there was something wrong with it becasue I couldn't hear any hiss from the EQ; was I ever surprised when I realized that it was working perfectly and it's sooo quiet. That being said, I've never used the DI part of the switch but we use several other Radial DI units in my band and they are extremely good. I'm sure the DI part of the Bone would be quiet and sound great. I see you use 2 basses so maybe you could give the Bassbone at try. It's a really great piece of gear for me and if it died or was lost or stolen, I'd buy another one at full price tomorrow.
Cheers!