1.6 Drive vs 1.6 D2

First of all, I do apologise as I know these aren't "performance" Volvos but I find this will be the place for the best answers.

Currently looking for another Volvo for my girlfriend, an economical, newer one. (She currently has a Volvo 340 1989).

She's adamant that she wants an R-Design but I've noticed they do a D2 and a 1.6 Drive. Only difference I can find is that the D2 is a 6 speed box, 8 valve engine and has a lot more torque for some reason.

I believe the 1.6 Drive is the PSA engine. Which one is more reliable?