Originally Posted by LukasM
That's a good list.
I would also prefer a semi-dry sump engine to avoid the extra complexities during oil changes and the weight of an external tank etc.
For braking power I think the stock Brembo caliper with a single 320mm disc should be fine for most people, it will be better than the 950 SE and the F650GS twin with less weight and better clamping power. The limiting factor is the mostly the tire after all, this is why the single disc F650GS outbrakes the twin disc F800GS, both have the same Brembo calipers as 950/990. And if you really want to put on a sticky 19" or 17" tire then just upgrade to a Motomaster caliper and you will have all the braking power you could need, without the extra weight.
If you want a really small light motor with great ground clearance where is the sump going to be? And how much oil is it going to hold? I'd rather not have a 1qt motor like an RFS for a adv bike... Nor would I want to worry about if the motor is running low on oil loosing oil pressure.
The 320mm disc is allot more likely to be damaged. The rotor is weaker side to side and lower making it more likely to get it by a rock or catch the ground in a crash... With a dual disc setup you also have redundancy in the system in the event you damage one rotor you can covert it to a single disc.
Not to mention it's not just about brake power, but about thermal efficiency over repeated stops...