I own a F650GS and I can tell you that is perfect for touring 2 up!!!
Yes, I know that 1200 is even better... but my little GS has near 15000 km and the only cons is the brake system so, having in mind that 700 has dual front disk... will not be your problem
I weight near 95kg and my girlfriend near 65kg... plus aliminium pannier and givi trekker 52 topcase
I you understand some spanish... take a look at my blog, I wrote about the F650GS and our travels :)