Bit of both, with the extra power I'm not overly keen on sticking to original axle, I have a s12 that I'm breaking so seems like a good idea to me. I like the idea of irs, rack conversion, ease of upgrading to lsd, the potential for a nice air ride install if the mood takes me. However I don't want to lose the practicality of the car so rear seat and load area need to be useable. A lot of the conversion I've seen aren't that great in that respect, the one above with the 510 is pretty good and I think the s12 rear end would work out pretty similar.