Well, at present they are but they r gettin a bit old now. It used to be v5's that were the best but as they get old the CDR reading capabilities get dodgy so as v7's get older i suspect a weakness will show through. (If u look on kelcoo there is a website that still sells new v7 PS2's)
To be honest if yr buying a new PS2 u have to go for the latest version (10) simply because of the extras thrown in it(Quieter,built in IR reciever etc), however the first thing I would do is carry out the romeo mod!
Regards