I use a Skycaddie SG2 and I'm very happy with it... Yes, there is a yearly subscription for it - but it's only $29.99 for the level I chose and I get 10 course slots on the device as well as unlimited downloads of all mapped courses in Florida to swap in and out of the 10 spots. It's been more than worth it for me. The first few times I played I had issues with the signal being too weak and the yardage seemed to be off by 10 yds or so, but after a software update and learning how to reset the GPS signals - I am more than happy with the accuracy. I am not good enough to care about 2-3 yds differece though - maybe someone who is a scratch golfer might need more accurate yardages.

It is nice to be able to get front/middle/back yardages for greens, but I really like knowing how many yds I have to clear a hazard or reach the end of the fairway on a dogleg... The best feature for me is the yardage measure where you can mark where you hit a shot, drive/walk to the ball and then hit a button to see how far from your previous spot you are... Gives you a better idea of how far you hit a certain club off the tee or even on lay-up shots...

It has really helped me - especially on courses where the yardage markers/sprinklers are lacking...