I drive my Z hard any time I feel the urge...that's why I bought it. It's a sports car. Not saying I thrash it everyday or anything..I haven't gotten a speeding ticket in over a year
(knock on wood)
I'd say I drive with synchrorev on about 80-85 percent of the time. The exhaust pops gloriously on the downshifts to stoplights. And seeing as how this thread is eleven pages long it might be a stretch to say "most don't have issues" ..I'd say this is kind of a big deal.
Also interesting to know gears 1-4 have more robust synchros..curious to know how you found this out? Either way..that might help explain why it's been the upper gears with the problems.