I would go in and talk to a dealer…don’t ask which one they would suggest, you know they will probably suggest the more expensive bike…you may be able to talk them into letting you test ride a V-Star 950 (that is a sweet one, I like it too), going from a 250cc machine to that one you will definately notice an improvement in accelleration…and you may not need the bigger bike…
I thought once I got used to my 500cc bike going bigger wouldn’t be a big deal, but I test rode a 1250cc sport touring bike (Bandit 1250S)…HOLY CRAP!! Going from my GS500 to that was like getting out of a Chevette and driving a Corvette…man, hold on…I decided that I just wasn’t ready for that step…and that was just a power difference, you are looking at a large weight gain as well which will change the riding dynamics on top of the more responsive engine. So, my suggestion is to take the middle step…you may find that you don’t need to upgrade from there, like Munch suggested. Those middle weight cruisers are very versatile bikes. They are fuel efficient, torquey, can tour and ride two up with no problems…unless you are planning on running at 100mph all day, but up to 80-85mph it will be just fine.
Good luck and have fun!!