Man, I'm almost 52 and feel the same way! Lol.

The 600's and up WILL bring out the 12 year old kid in you, so you really need to be aware of the proper time and place. The F4i is "less" of a sports bike in the sense that a 90's Porsche is "less" of a sports car than current models. It's plenty fast (and most who say 600's aren't enough are straight-line riders) and more than capable in the corners. I rode a Ninja 300 for a year before moving up and the biggest issues for me were getting used to the weight and the dual nature of the throttle, i.e. pretty gentle down low in the rpms, screams in the upper range.

Take your time, watch a **** ton of "new biker" vids, and work on slow speed skills in a nicely paved parking lot. It seems counter intuitive but getting comfortable with balance, swerving, and emergency braking at low speeds does translate well to faster riding... and you won't look like a goofball the first time you have to do a sharp u turn...

Good luck and show us some pics when you get her!

 

F4i is well mannered and comfortable but very fast. Don't be fooled by its age (or the existence of the RR).

 

They'll have helpful advice to try to find someone who rides in your field.
A bike is an amazing purchase. I know that there are a lot of arguments for local business support, but I have always noticed that bike shop bikes and services are overpriced and don't forgot to check supercross and motocross similarities also. Get a used bike from an online discount bike shop like Nashbar on Craigslist or a new one. In your current price range, nothing wrong. You're going to have to learn how to tune it and manage it, but to get you started, it will do the job.

 

A bike can be a really great purchase! I understand that there are arguments in favor of supporting local businesses, but I've personally noticed that bikes and services at bike shops can sometimes be expensive. Don't forget to explore the similarities between supercross and motocross as well. One option is to consider getting a used bike from an online discount bike shop like Nashbar or checking out listings on Craigslist. Alternatively, you can look for a new bike within your current price range, and there's nothing wrong with that. Just keep in mind that if you go for a used bike, you may need to learn how to tune and maintain it yourself. But it should be sufficient to get you started on your biking journey.

 

Like any car, a CBR600 will go faster than you are allowed in any situation, but unlike a budget 300cc, it has good brakes, bigger tires, and good forks, and you won't have to wring its neck when you get on the motorway, and it will "point and squirt" much more controllably. It's a mile-muncher, a Honda Accord - it will go forever with occasional oil changes and tires.

You could still be riding that 2002 CBR in 20 years time, and it will still be worth pretty much what you paid for it if you keep it in the same condition.

If you're going to ride with a bunch of young idiots, be careful - it will get you into trouble really really quickly. If you're going to cruise around, it will be solid, reliable, and more capable than most of us mortals.

Go for it - if you don't love it, flip it. The only thing you need to be careful of is not grabbing a full handful of throttle or brake, but that's true of most bikes over 125cc.