hi dave,
I had really enjoyed the original BX with the UK upsidedown rear mod and the 0,5 rear hub, it make the car very stable.
I can't compare it with the BXW because i have only raced once and the conditions was totally different (wet and muddy track) and it keeps on raining in france until now.
But i found the bxw easier for accessiing to the diffs and maintenance.
And in my point of view, i found the bxw prettier...