Monster sizing vs other bikes

[Blackout]

I'm biased as hell. I started out with a Ducati 800 which I still have. I love that bike, it's got more hp than your 620 in roughly the same sized package. My bias comes from my Speed Triple. It is simply the best bike around for my use. The engine is a colossus, it handles beautifully and is forgiving. It makes power everywhere. It's not geared for top end power so only goes about 150 top speed, slower than my friends with R6s. The S3 is a larger bike, weighs a little more than the Monster but the stock cans weigh a ton so remove them immediately. The seat height is probably 2 to 3 inches higher than the Monster as well.
I've also ridden the Sport Classic and cool as it is it just didn't do it for me.
If I had to get another bike today I'd look at the KTM SuperDuke or even the new 1100 Monster. My 2cents.