I would say that having the ability to choose between (-) and (+) would put it ahead of any (-) or (+) drive, it's up to you to decide if you want to spend the extra $$. I haven't seen any benchmark results, so I would guess that the speed of the drive is very similar to other drives.
also there is a software upgrade (free) to take +R to 4X.
One question. If Sony has decided to enter the -R/-RW market, why hasn't Pioneer and company released a +R/+RW counterpart if +R/+RW is a way to go? hmmm... I am wondering if the + capability will be worth the extra $40 to have???