I'm about 210 and I ride aggressively... had a 250 GTS (I've tested the 300) and a BV500. I took both of them on several extended highway trips of 300 to 500 hundred miles. Both did very well. I'm thinking about my new ride for next year as I write this... 300cc's is not enough for me. Yes it will keep up to traffic but there is very little in the way of get up and go at high speeds. I want more in reserve than 278cc's can give. I must add that at least 60% of my riding is at highway speeds though.
I've got my eye on a Peugeot Satelis 500 at the moment. (BV500 drive train)
Dave