I originally wanted the Nismo LSD. We installed one on my friend's S13 and I was way more impressed than I thought I would be.
I really do get why you want a 1.5. Thats what I wanted originally but it just wasn't an option. I drove other cars after moving to a 2 way and it really wasn't as bad as I expected so I went with the Kaaz. I just never got around to actually installing it.