OK, I'll bite...
First, cards on the table -- I'm founder & CEO of FXpansion, the people that make BFD.
Back when we recorded BFD, I had a pretty heated debate with Steve Duda, the recording engineer, about the whole LH/RH thing. I was very much in favour of including them, but he was against, on the grounds that there's no timbral difference between LH and RH hits, it's all down to how hard the drummer strikes the drum (and the fact that they hit harder with one arm than the other).. and as such, it's better to have 80 generic samples than 40x LH and 40x RH, and then simulate the whole LH/RH thing with velocity variations (in your drum programming, in the software...). In the end, the only thing to do was put it to the listening test. Steve was right, I was wrong.
Bear in mind that the V-Drums systems that are very popular these days, even a $4800 TD-20 rig, have NO way of telling LH from RH*. Even if you're triggering DFHS. There's no way of magically regenerating that information. They still sound 100% convincing though -- at least when triggering any of the big sample libraries -- because they pick up the velocity variations, and that's all it is. So, in those nice e-drums videos on Toontrack's site, unless I'm very much mistaken, you're just hearing RH hits regardless of what the drummer plays (again, the drum brain has no way to tell the left stick from the right, and so can't generate different MIDI information for one or the other). Same goes for drum replacers and "bug" triggers.
If you're programming, or keyboarding, your drums, it's very easy to simulate this with BFD's keymapper -- just assign a second key to any drums where you want two 'hands' on the keyboard, and tweak the velocity range on one a little.
I'm not saying that DFHS is without its pluses, but the whole LH/RH thing is bogus. 20xL and 20xR is better than 20x neutral, but 40x neutral is *much* better than either.
Hope this helps,
Angus.
* You could possibly do it on the kick by using a pair of cheap switch-action kick triggers (like those off the TD-3) and remapping things, but anyone given the choice tends to get pad-action kick triggers which don't know L from R.
