I have a vermeer 252 and switched from the vermeer tooth to greenteeth a couple years ago. Huge difference in productivity and much less time to change teeth since you only loosen the dull tooth and turn it 1/3 to a new edge. It's now much easier to keep sharp edges on the machine; thus, it appears to me that there is also less wear.
Now, that said, here is the subject of debate as far as greenteeth go - some will say that the use of greenteeth shortens bearing life because the teeth are too aggressive. I agree that the teeth are much more agressive than the factory vermeer teeth. However, on my machine, the autosweep feature keeps the teeth from taking too big of a bite. In return, the machine doesn't seem to bog down and beat up bearings as is probably happening on machines without autosweep.
I've read on this forum that a lot of guys disable the 'autosleep' feature (as they refer to it) because they think it slows down production. Yet, these may very well be the same people complaining that greenteeth cause excessive bearing wear.
I don't know who's right and who's wrong about greenteeth and about the autosweep feature. All I can tell you is that I'm using the 700 series greenteeth (1 1/4" size) on my machine which is equiped with the autosweep feature and I feel the teeth are very productive and have not caused any excessive wear to my machine. Because of the autosweep, my machine very rarely every bogs down, jumps or kills because it takes too big of a bite.
Since buying my greenteeth setup a couple years ago, the manufacture now recommends the use of a smaller sized tooth for my machine (and probably the 630 vermeer as well). They recommend the 3/4" tooth which I believe is a 500 series. It's supposed to be less agressive and work better on the smaller machines.
Others might recommend changing to a Sandvik wheel or some other setup. I won't dispute that the other setups also increase productivity. However, with the greenteeth setup, all your changing is the pockets and teeth - probably a $300-400 setup. Change out the wheel to a Sandvik or other setup and your new setup jumps to $1000+. Maybe worth it but, the question is, 'how much do you want to invest'?
I'm sticking with the greenteeth. That's all anyone uses around here and for one simple reason - it's a darn good setup. You just have to be sensable about how you treat your machine. If you have autosweep, I'd highly recommend keeping it enabled. I also have a Rayco 1625 Super Jr (same thing as a vermeer 252) and I have the 500 series greenteeth setup on it. It doesn't have the autosweep feature that my vermeer has so I prefer to use my vermeer. With the rayco, I have to pay more attention or I'll take too big of a bite and 'climb up the stump'.
Sorry about the length of this post. Hope this gives you the insight you're looking for.