I "never" experienced pinch flats on my clinchers, I think that punctures on my tubs are just about as common as on my clinchers.
I think that the different experiences people have also comes from the different kind of debris that is on the road in different parts of the world. Here in denmark we have a lot of small knife sharp flintstones. I regularly remove them from my tires and they leave lots of smaller and bigger cuts.
Also the rider weight and how good you are at avoiding potential puncture spots matter a lot I think
- Based on my experiences (62kg, pretty good at jumping potholes/debris and cleaning tires while riding).
Advantage Clinchers:
1) spare inner tubes take up much less room than a spare tub - So I most always bring two for longer rides.
2) There is no preperation associated with clinchers (just buy, mount and go)
3) I ride more "relaxed" on the clinchers, as in I don't take as much care with where I ride when training - Because the only hazzle with a flat is to replace the innertube, there is no risk of having to redo a gluejob or throw out a $80 tubular.
Disadvantage Clinchers:
1) Clincher wheelsets are always heavier than their tubular counterparts.
2) Some tire/rim combos are just a pain to mount! Much more so than my tubs
3) When in a hurry doing a repair, (dont clean tire throughly or if innertube get caught in tire) I have flatted again instantly when pumping
Advantage Tubs:
1) Lighter wheels
2) Much easier to find a good deal on a highend carbon tubular wheelset than the comparable clincher versions (I bought my 202's used in a shop a couple of years ago for around $800 (2008 model)), never seen any good deals on Zipp clinchers (Neither new or used).
3) Ride quality/feel (for the price I guess)
4) Often faster for me to change a preglued tub than to change a inner tube.
5) The small amount of liquid sealent I have in the tubes sometimes make sure that I don't even notice that I flatted.. Don't run liquid sealent on clinchers...
Disadvantage Tubs:
1) Preperation - tubulars need to be stretched and preglued, and every once in a while rim needs to be cleaned and glued up from scratch again.
2) You need to bring a spare pre-glued tubular on long rides, unless you can get a lift home (Its not all punctures liquid sealant can fix)
3) The liquid sealant that you absolutly need here in Denmark, age and loose its effect.
4) Like everything else it takes a bit of practice to mount/glue tubs correctly and quickly.
5) When training I sometimes find myself a bit more careful with where I ride.
I love my Zipp 202's and ride them as often as not. However I also use my clinchers a lot, mostly when the weather is bad or when I have a flat on the tubs and the gluework needs to be redone completly. Then I ride clinchers until I feel like cleaning and glueing the tubs, lol..
I don't know what the conclusion is.. Clinchers have the ease of maintance going for them IMO (no cleaning of rim/preglueing stretching). I like that, but on the other hand the tubs feels great and a good used cabon tubular wheelset can bet gotten cheaper than the clincher versions..