I've not done enough miles to comment on the R9T, but I have done almost 100,000 on a Twin Cam GSA and RT (same engine as the R9T).
Mine generally used about 500ml every 6,000 miles. Maybe a little more when the bikes were quite new.
I had another RT that used a fair bit more oil; a complete pain on longer trips. It had done about 6k from new iirc. I changed the oil for standard mineral oil, rode it fairly hard for a couple of thousand miles (plenty of full throttle and load on the engine), then went back to semi-synth. It's oil consumption was vastly reduced.
My 9t is just over 2500 miles, it used 750 ml on a recent 2000 mile trip to the french alps,
Expected a bit as a previous gsa twin cam and 1150 gsa used a little,