I've been trying a bunch of tips lately.
First off, ozone sold me fake moori tips in 2008. They are the worst. Don't hold shape, glaze, mushroom. They just sucked. These fakes came with a gazillions layers marked "M". Boo!
Next, real moori mediums. Ok, still mushroom but not as bad as a LePro. Really nothing that special, but have the hardness I like.
Ultraskin Med. I like. So far no mushroom. When you trim they leave "filings" which is a damn good sign. A tad hard for my taste, but they play good. Great deal. A great replacement for genuine moori medium, just a hair harder.
Tiger Onyx. Really, really great tip. Nice and soft but doesn't glaze at all. No mushrooming at all, holds chalk really well. It's on a mega pro taper shaft, so I seem to miscue a bunch, but I'm not sure I can blame it on the tip.
Pooldawg8 milk duds. Really, really great. They are a little harder, but play fantastic (they sorta play softer than they are). They seem to glaze a little more than the onyx, but on the same taper shaft miscue less (literally brought the other shaft to Klein and had him cut this one down to match the other mega pro taper). I doubt these will mushroom. They hold chalk really, really well. This tip gives me the most perfect kerplunk sound/feel that puts me in the zone. When they glaze, just chalking well brings the surface back, no need to sand. During practice I can go about 2 racks without chalking before I see any glazing.
Samsara break. This is awesome for that purpose. Super hard, chalk sticks (for a break tip), can use it as a player in a pinch (just chalk often). Jumps well.