I use triangles and start them low 3/32" tall plus the crown. So there isnt much there to start with. Usually I get about 100-150 hours of play before they are worn out (down to the ferrel). They mushroom about 75% of the time, but because I start them so low there isnt much to trim. They never mushroom twice. That's that average. I would say that this is the case 70% of the time.
The other 30% I get bad tips that get hard or mushroom too much and they last less than 50 hours, it takes about 20 hours to break in tips, so 99% of the time the first 20 hours they are fine, but I dont use new tips if I'm in action.
Once in a while I get a good one that wont mushroom and dosent glaze over, thats rare. I just had one that lasted about 300 hours. I wish I would have started with more than 3/32"-It was the best tip I have had in years.
Anything over 150 hours and no mushroom or glazing is what I call a perfect tip and they are rare, I havent been able to determine these traits until the break-in period(about 20 hours) is over. I wish I could that would be great if I could, but until a tip is used you never really know. There are ways to sift through a box of Triangles and toss out the bad ones, usually there are only a couple good tips in a box of 50. Layered tips are much more reliable, but I dont like them.
Like Scott just said its different for everyone. I like Triangles, some are crap, others are great. I switch them out often cause I like low tips. I decided after I played for about 2 years that I like short tips. Just a preferance of mine and a few other guys I have known, some champions, others are C players. There is no right or wrong in tips, its what works for you.
But I will say this, not all tips work on all cues, you have match the hardness or softness with the hit of the cue. Like JA says "The tires have to match the wheels, same for tips on a cue". There is lots to be said for that, if I put a real hard tip on a Black Boar it would not work. Tony makes his cues to play best with Triangles that are med soft. There is no formula it varies from cue to cue, on SW's I like harder tips as a rule. I put a Elk Master tht was real soft on a SW once, it made the cue play terrible, the tip didnt match that particular cue. To complicate things things even more; I have hit balls with real hard hitting billiard cues with soft Elk masters that felt great. Go figure???
there are way to many variables and conditions to talk about all of them, when you have a good tip-life is nice.
I'll throw in a few more thoughts; Find out what works best and roll with it, I have had tips last a year when I started them tall and they were good tips. When I' play lots of 1P tips last longer than when I'm playing 6ball or 9ball. So what game you play also has a big effect on the life of a tip. I never use sand paper on a tip or a pik. I use a old school tapper, But roll it just enough to get rif of the glaze not removing any leather or causein premature wear of the tip.
oh here is a good one, Kamui chalk extends the life of a tip, with out a doubt because its not abrasive like other chalk, its creamy like make-up. So I noticed my tip almost never glazed over with Kamui, it might after 4-5 hours of play. Same tip did glaze over every 90 minutes with Master Chalk. I didnt get the Kamui whan I had that real good tip, I'd probably still have it if I did. It just wore down to the ferrel by chalking only, I never once had it glaze over, the only thing that touched it was the CB and chalk and it wore doen in about 300 hours of play(wow that was a dandy of a tip).
these are my experiences with tips, chalk, scuffers etc. I pay attention to this stuff as it interests me. Sounds silly but I think its kinda cool. Even when I'm in big action, I was tied up in a game for a couple weeks in March, during play I would look at my tip to make sure it was ok. but after each session I would carefully look at it and made mental notes about it. Its fascinating for me. Some guys couldnt care less and I respect that, I just like to see how things work and last.