I had the 650 for a few years and did 80 000km on that bike, my longest trip was 59 days through Nam, Bots, Zambia, Malawi, Tanzania & Moz, the bike did'nt even use oil.. flip those 650's are bulletproof and you can load the hell out of them, I never had a day's issue.
Not that I like to compare bikes but the 650 and 700 are as similar as they are different. The 700 is an upgrade if you consider that it has more electronics, digital dash, ABS etc. Also being a fuel injected bike. Other than that, it is the same bulletproof bike.
I think for me the 700 was not seen as an upgrade, they simply stopped making the 650 and launched the new 700.
My 2c