Considering that I went through three TurboDuo's in my lifetime (the CD drives kept dying on me), I *hope* the PCEngine's aren't any shoddier. (I've moved to a modded SuperGrafx + SuperCD + arcade card system.
I've had the same Turbo Duo since the year it was launched.
I've treated it like garbage, literally smashed the shit out of it(I've crudely patched up the back side where I first ripped out the AC Adaptor board and then carved up a hole trying to "fix" it as a teen).
I've wiped the lense with a cloth before I knew better, I've let it get dusty, for years I'd pop the lide and forcibly stop the CD from spinning, while cleaning it once I pushed too hard and puched one of the plastic vents right through... and a lot more.
And it still plays flawlessly and can handle pretty much any cdr(although I pretty much only play originals) game I throw at it. Where as my PCE Duo RX can't really handle any cdr games.
Also, I had a spare Duo that I played to death for years and never had any problems with it either.