I'd be more than happy to purchase a Quaife LSD. The're in Sevenoaks I believe which is local.
The plate diff in my NSX ('91) lets the inside wheel spin like crazy on tight corners and really is a bit too loose for the track. Its pretty safe though.
I have a Torsen diff in the supercharged MX5 and that will not let this happen on the same track. It's definitely better IMHO. The rear end of the MX5 developes real 'bite' in tight corners, whereas the NSX will just let one wheel go. Sticky rubber and the 'R' suspension has reduced this tendency greatly.
Mo