After trying a friends classic I knew I had to get one and it had to be one with a counter.
The Pro's are the ones to go for. The Pro models all have counters and Neons have added led's which which slows the Ball down by about 200-300rpm. So far that reason this is the best one to go for unless you want some cool lights like I did. I still recommend one of these for you getting your best scores and keep others for practice.
It doesn't take long to get it going and get a feel for it, only took me a few tries. It's perfecting your technique that will take a while. When I first used the classic It almost gave me little blisters and you will get them with Powerballs, but I think the grip on this is better as I haven't felt it rubbing on my fingers as badly. Might just be me though. Yo will probably have to give yourself a days rest from Powerballing to let your muscles recover and keep your hands blister free.
The digital counter is a must have. It has different functions and can store your top score. If you don't beat your high score it will just clear the lower scores anyone gets. It can be reset at the touch of a button. the counter will switch itself off after 40 seconds of inactivity, prolonging the battery life, which shouldn't need changing in a long time. You can also measure your rpm's over set times of 30, 60 and 90 second intervals + more.
Get one of these balls now, better still get two for dual Powerballing. Get recoring videos of your runs and become part of the Powerball community. Great fun and exercise from a revolutionary product. Get yourself a leather pouch as well to keep it in good nick, you get two starter cords included. The Pro's are the way to go.