From what you say, I'd say you might prefer the Z rather than the R. It has more wind protection, a little more road presence and will be the better road bike for the high-ish speeds you say you want to do, which it will do happily all day long.

The R version is smaller, lighter and more agile and that comes in to its own off road and is more playful. You can throw it down in to corners more easily. But the Z will do the same terrain and in some ways is slightly more off road ready out of the crate, but I'd not worry about that too much.

On both bikes a single can will save a tonne of weight (not literally of course), and when combined with the Kev mods and a decent air filter, will transform the bike.

I went for the Z. My friend went for the R. We just did a 1300km trip together on road and off and both bikes did brilliantly. I wouldn't swap from mine, but neither would he from his. I'm almost 6 foot tall and came from a GS1200 and wanted a bike with road presence and touring capability and was happy to accept more weight and a little less agility off road for that. He is shorter and wanted to focus more on lower seat height, lower weight and the ability to ride more aggressively off road. (He's an ex national level moto x racer, so has lots of ability to ride hard and fast off road.)

I hope that helps...?