We were in the middle af a long arena tour when I got the RBI and aded it (i thought I might make my rack set-up more compact)...
I switched during set-up and, during soundcheck the FOH engineer from WAY back in an arena said "how come the bass soundes different today?"
Which shows he's listening!
Anyway, at that point I told him and we did a quick A-B and he was adamant that the BDDI sounded "better".
So next break I had, I took the rack into Pie Studios, where I could listen for myself and really know what I'm hearing, and we ran both into the Neve and listened.
And there as well, it was clear that the RBI was somehow more hollow and transparent.
So I've really been using the BDDI ever since...
One nice thing about the RBI is that if you use the effected output to feed your amp (I DON'T) then having that separate level control for each output is a big help.
In fact I wish it worked on the parallel out, but it doesn't.
But I use the SansAmp to make the DI sound more like the amp. Not to change the amp's sound in any way. (which, being a Hiwatt, is perfection {g})