Keith,
The 200 is a 5" prop, 30A ESC bird. The 150 is a 3" prop, 20A ESC bird. They are quite a bit different in size and power. Remember, all of the flying I've done so far with the 200 has been with 3S 1300 not 4S. I just got 4S batteries for it but haven't flown with them yet. If you think my bird looks fast now when I'm not even hitting full throttle, it's going to be a rocket with the 4S on there. You're going to want to really take it easy starting out with 4S batteries and the GT2 200 as your very first bird.
Jerry