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@graeme_the_bike_tech
Admission up front of bias - I run Campagnolo's main UK Service Centre.
"found it a bitch on a couple of steel frames-carbon was fine. Think it's just BB shell width variance that allows the axle to shift creating a clicking when you pedal under load (yes I got the BB shell faced before install etc.) I read a lot of other folk had the same problem."
It's not normally a problem unless the BB shell width is a lot under tolerance - if the face-to-face width is less than the design minimum of 67.2 mm, then yes, the wavy washer can't take up the end float.
I have several UT bikes that are ridden year-round and have had worse bearing life than with square taper but that is also true of other "outboard" and "oversize" (BB30 etc) systems that I have tried and that my customers have fitted. It's a consequence of taking something initially developed for competition and using it in ways that it wasn't really originally destined for. That's what a large sector of the market demands ... I am not saying that it makes any sense, mind ...
Skinny - the point of the PT design was to keep the pedal width ("Q factor") the same as with the square taper BB designs but at a more aggressive price-point than UT.
UT did this by building end-float adjustment into the cup, rather than using the cumbersome (and rather poor, in engineering terms) solution that Shimano have adopted. This was the point of the Hurth joint - not simply difference for the sake of it. PT is a variation on the same. Unfortunately, to maintain ankle clearance it wasn't possible to build in a self-extractor.
Pulling PT has also attracted a lot of comment, but in fact it's easy IF you use the right puller (Facom U.301) and if you remember to remove the washer under the head of the bolt ... we have had a lot of cranks back that mechanics have said were "impossible to pull" but in general have found the remains of the washer squished in there. The remainder have been fitted dry when the technical docs do say that the crank should be greased.