I went poking around the internet about a year ago searching for the tips the pros use. As I recall, the brands and types were as varied as with players at a local room. A little bit of this, and a little bit of that.
Lately I've heard Moori mentioned every now and then. But then I read about a pro who had no idea what type of tip they were using!
In some older pool books, they mentioned better players who would install a new tip, then bang their shaft on the ground 100 times to make the tip hard.
I read about someone who soaked their tip in half and half milk for 24 hours, then compressed his tip in a vise to make it hard. The half and half had some sort of stuff in it which would hold the tip together and keep it from delaminating (as it wore down).
The idea behind this was to play with a consistent tip. (This was in the days before the new high quality tips now available.)
I think the question to ask is if the pros always play with the same brand and hardness of tip. And what do they do to keep their tip maintained?
Different tips will play differently. So I would assume that they probably stick to one brand/hardness, have learned to play with that tip, and probably are not eager to go switching to other brands/hardness.
I think the best thing to do is to experiment with different tips. Soft, medium, hard. Different brands. Leather, pig skin, etc. Different shapes on tips, dime, nickel, quarter. Then learn what works best for you. And then *stick* with that brand, that hardness, and always keep your tip the same radius (nickel, dime, etc.)
I think that always playing with the same exact tip will go a long way towards consistent play. And when you replace your tip, it will have the same radius and will play the same as the old tip.