Hi Brian,
Maybe this will help you in some respect. I have posted two sound files with examples of 1. a timpani motive: www.musesamples.com/testlib/OrigamiTimp.mp3
and 2. a drum roll followed by a hit: www.musesamples.com/testlib/OrigamiDrums.mp3
I used the Origami tool by Yellow Tools which has a kind of space positioner.
You will find the examples resp. a. without reverb at all; b. in front of the stage; c in the middle and d at the back of the stage. The overall sound seems to be altered in relation with these placements apparently. The less direct strike in the percussion sound d is maybe different enough (from the original sound I mean) for you to stay with the VSL.
I hope this will give you at least some more and relevant information.
I guess this is the same Brian from another thread here somewhere: I would like to express here my compliments and respect for your splendid version of the Elgar theme. Really a great job, very musical and expressive.