well, I've had all three in this order; f650, wee strom, tiger.
The F will be almost like riding your bike now. I loved it until I rode something else for a couple of weeks. But I would buy another one.
I personally hated the wee strom, It was big and plasticy, and didn't have enough top end, and all in all felt unwieldy. I rode one at sea level for some miles and liked it but here at altitude, it was weak.
I now have a tiger which feels like a dirtbike on steroids. Feels like the F but heavier and more powerful. It still handles like a dirt bike and doesn't have all the jack plastic crap that you break when you tip it over.
That's my opinion and everyone knows opinions are like assholes, everyone has one and eveyone else's stinks.