I have the Corbin version with heat. Other than the heat, stitching and dark blue piping, it's pretty much identical I think. I love it. I'm a commuter so most of my riding is limited to a half hour each morning and evening (more or less). I think my longest ride on it has been about 1.5 hours. No discomfort.
It's quite a bit stiffer than the stock seat and much heavier. To me, it feels really solid and nice, like I'm plugged into the bike better. If anything, it's a little easier to (purposely) slide to the inside on turns than stock. But it's just as easy to stay planted if you prefer. The pillion end is a little loose when you stand next to the bike and try to move it. At first I though about returning the seat. Then I realized that the extra play is needed to release the seat from the seat lock. It doesn't move around at all when you're on it.
On the downside, its forward cant is similar to the stock seats and there's a tendency to get pushed into the tank (like stock). But I've noticed my posture has changed a little over the several hundred miles I've used it and now it's pretty natural to stay back in the bucket.
If you get it and ride in the rain, think about getting a seat rain cover from Corbin. I live in the Seattle area so I'll keep my rain cover on for...oh...the next 8 months or so.
If I hadn't gotten the seat heat (not available from Yamaha), I would have bought this version from Yamaha. It's much less expensive than getting it from Corbin.
It looks like you've got a couple other questions.
No, I don't think the Yamaha version is any lower than stock. There is a Corbin Close version that I think is a little lower. This seat is more optimized for riding and less for putting your feet down. I think there's some extra width so it may feel like you're a little farther off the ground. But I don't think you are.
It's a one-piece seat, so you get the passenger seat attached to the riders seat.
You don't get a (passenger) backrest with it unless you order a backrest. It is backrest compatible whether or not you order the backrest.
It comes on its own pan. You keep your stock seat.