The 500 would be more attractive to me if there were a weight savings as compared to the 750. But if the released specs. are correct regarding the 500, and the leaked performance numbers are correct regarding both models, lower-thirties on a 480 lb bike could be really, really compromising; either at the top end or in acceleration; or both. I've looked at those new Honda CB 500s. According to the dyno tests, those models are at or about 47 horsepower, weigh from 420 to 435 lbs, and are priced from $5,500-$6,000. The Hondas, however, are not even close with respect to the attention to detail with respect to finish and paint from what I can tell with the pics.
I am by no means a sport-oriented rider, however, most any 500 cc is going to have a little more hp or a little less weight. Even the Kymco Xciting 500 scooter is 473 lbs and 38 hp and it's fully accessorized in stock form, so one would not be adding any weight after the sale. The Piaggio BV500 comes in at 39 hp and is much lighter; it's also a scooter. Of course these scooters lose a little due to a less efficient drive train.
If I were strictly an urban rider though, I'd might opt for the smaller ccs and save some money. But for anyone who plans to ever hit the road on this bike, I think one might be a little disappointed in how the 500 performs out in traffic out in the open. Of course we won't know for sure, because those leaked performance numbers could be deceiving, but just looking at it, 480 lbs is a lot of weight for that kind of power at higher speeds. If mid-range torque were particularly high in combination with that power rating, that might be something to consider, but according to the leaked numbers, that's not the case. The torque seems about average for the amount of power output.