I had the chance to demo an Optishot and it's a really neat system. If I had the space I'd seriously consider buying one.
However, a few things to be aware of. First, you need a room such as a garage that doesn't get much (if any) light. The sensors don't work right if they pick up any sun. To be honest, even at night in my living room I couldn't get it to read properly, and that was likely because the light was just not the right type. Secondly, to optimize the system and actually play the high level courses and hook it into your big screen TV, you need a pretty high-end computer built for games and with a good video capability. My Dell laptop couldn't handle it, so the most I could do was the driving range, which was still cool. You can see swing speed, face angle/path, ball flight, etc. I was able to take full swings in my living room, even with a driver, but it's hard to make a comfortable swing without plenty of room around, and even the foam balls really rocket off walls and stuff and while they wouldn't break a window or anything, they could knock something over. Finally, think of a way to build up a stance, because the mat is about 2.5" thick, which would surely make throw off your stance if you're on the ground and the ball is a couple inches higher.
Don't get it as a substitute for a Trackman, but as a game, I could see it being really fun if you've got the space and the computer capable of handling it.