I've been swooned and in blissful honeymoon with 633 ever since it came out and got rave reviews on this forum.
However, many of you are going to disagree with what's about to come next.
One day I went down into the basement and remembered my Lift 150, a wing that has been gathering dust down there ever since the introduction of the 633. I put the Lift up for sale a bit earlier. Not sure why, but for the sake of "science" I decided to compare the two wings that day. Well, one session turned into two, then three, four, five, etc, etc. Now, after five months of comparing, I'm completely blown away. The 150 is a MUCH better foil for waves and freestyle. It's not even a contest. It's more carvy on flat water and waves, is more weight-balanced, is lighter, faster, boosts better, tacks better, and just results in a much bigger stoke than 633.
That said, the 633 is still an AMAZING wing, but in waves over 5-6 feet. When waves are close to overhead, the 633 comes to life and blows away the 150. On big waves, the 633 can keep a slower, more controlled speed when down the line. The stoke during these rides is just insane. As an added bonus, the 633 also keeps a more stable ride in white water. In light winds, the 633 has a 2-3 knot lower end than the Lift 150 (and even Lift 170) and has become my foil of choice when winds are below 10 knots. I modded the 633 rear stabilizer with a 2mm riser to help shift weight from front. When waves are less than 4-5 feet, however, I'll always go for the 150.
I still LOVE both foils, but now, for different purposes. The above goes contrary to what many of you said about the 633, but I do believe, if you give 150 a good chance, you may agree as well. Wanted to throw it out there for you to discuss.