I’m a bit heavier 175lbs, riding a 138x42 JT Pro TT and 12m razor; I don’t think I’d be able to ride in 8-10mph, but the kite will stay in the air if it’s already up. Launching any kite in that light of wind can be difficult, especially nose down in the water. It is rideable in the 12-15mph range, but it really comes down to board and kite skills/experience. One of the girls I was riding with in light wind (who only weighs about 110lbs) really didn’t like the razor at all and had a hard time staying upwind, but put her on the rise and she had no problem (she’s been riding the Rise for about 3years, although intermittently). When she handed the kite to me in the same wind conditions it was a very doable ride, with no problem staying upwind, but I found I was moving the kite a lot more than she was, and a little bit more microadjusting the trim made a world of difference. So yeah, it’s doable. I don’t think I would make the drive out to the beach if that’s all the wind was doing. If I was out and the wind lulled down, I would be comfortable making it back to shore.
I paired the 8m razor with the 12m razor. It’s a good match, with nice overlap in the mid range. For unhooked and powered tricks, having the right size for the right wind conditions makes a world of difference, so yeah, I still daydream about getting a 6 and 10 razor to round out the quiver, as excessive as that might sound, but there are really no days missed with a 2 kite quiver. I did keep my older rises just in case the gusty factor made a big difference, but so far I have been very satisfied with the razors. Hope that helps. Let me know how that 15m Rise performs when you get the chance!