I using the original tip that came with my Huebler, I think its a LePro.
PM Duc Lam, aka CueMaster98, he can probably answer your questions as he also list them in the ForSale section of this forum. Duc's favorite is the Molavia Hard, he believes it plays just like the old discontinued Moori Medium Hard.
Mueller carry Molavia, here the link along with their hardness rating along with hardness comparisons for other tips they carry.
I was shooting with a Super Pro, which I liked, and just changed to a Black Kamui Hard. The Kamui is softer than the Super Pro and holds chalk better. I'm not very particular with tips. I like the Moori Mediums and the Wizards - don't like Le Pro or Elkmaster tips.
Molavia{H} is what i have on my lp custom. They hold their shape very well and get alot of action. but you have to work the tip alot with tip pick or tapper because some of them get slick. But its worth the results and you will never have to worry about delamination. Moori{M} and Triangles are also my choice. Depends on shaft and ferrule.
Triangle, I just had a red pad put on and I think I like it better too soon to tell, I get about 100 hours of play then change to a new tip. They get a bit hard after a while, some last longer than others. Once in a while I get a bad tip-not to often. I'm not into layered tips.
Recently, I have been hearing some good things about the samsara. Considering putting one on my J/B. Feedback? Good or bad, would like to hear what you have to say.
I had a lot of miss cues with the Everest that came with my Z-2. I was always shaping and roughing up the Everest. I think it was too soft. Now all I use is a tip pick on a Le Pro medium before I play. I may need to re pick after a few hours. It gives me a better feed back then the Everest ever did. Straight pool mostly, 9 ball, yuck and some 8 ball. I break with a house stick with a Le Pro also. I also went from a dime shape to a nickel shaped tip.