If you end up hating Tokyo, there are plenty of day trips you can take to not-so-urban nearby places. Also day hikes, to places like Hakone or Mt Takao.

I happen to like Tokyo so always can find seven days worth of things to do. On the contrary, seven days in Kyoto would be too much, I'd be templed out by the end of the third day.

For me, the main concern about which to do first is jetlag. Where would you prefer to get over jetlag?