I have a 1999 subaru forester. I had the clutch replaced in january of 2006 with 80,000 miles on the original clutch. I took the car to a very reputable mechanic but not the dealer. He put in a new after market clutch for 1,100 saving me a few hundred bucks. I now have to replace the clutch again and in talking to the dealership have discovered it is somewhat well known that non factory clutches wear quickly in subarus. I have the same garage putting in a factory clucth but only at my request. My wife and I have both been driving a standard for over ten years, does this seem like a sub par product was used? should I continue patronage at the same garage? Shoud the garage have used a factory part in the first place? Should they have known about the non factory part wearing quickly or atleast suggested using a different product the second time?
“in talking to the dealership have discovered it is somewhat well known that non factory clutches wear quickly in subarus.” How convent. It may be true, but I have not heard of anything like that. I could consider that statement very suspect.
How did each clutch fail? What part?
The dealership is flat our wrong in saying that non-factory parts wear faster than factory OEM ones. No doubt a service advisor told you this. They may not be lying to you but may sincerely believe the misinformation they are doling out.
There are several reasons for a premature clutch failure. Improper adjustment or free play in the clutch hydraulics, warped or burned flywheel that was not surfaced when the orig. clutch was replaced, failure to replace the clutch disc, oil leakage from a transmission mainshaft seal or engine rear main seal or plate, etc.
There is also one more reason for an early clutch failure and this is peculiar to Subaru. The throw out bearing guide sleeve (a mount basically) is designed to slide on the protruding nose of the transmission. The nose is aluminum and the guide sleeve is steel. On the inside of that sleeve is a machined grease groove for lubricant. The edges of this groove are sharp and it’s possible for the steel to dig into the aluminum and cause the sleeve to bind. This can prevent full disengagement of the clutch.
It’s something not many know about and chances are even the dealer or dealer techs may not know. Every time I’ve done a clutch job on a Subaru (done a bunch too) I always round those sharp edges off and repack it with fresh grease.
There’s not enough info provided to know the cause but it is a shop’s responsibility to inspect all of those things I mentioned when doing a clutch job, no matter if it’s a dealer or independent shop.
Hope some of that helps. 
Aftermarket parts often don’t last as long as the OEM parts, but your difference is dramatic beyond the norm. It’s possible that there was a misadjustment or that the surface of the flywheel was scored from going too long with a worn original clutch, but these are just possibilities the probabilities of which are impossible to guess from here.
Or, he may simply not have known that the Chinese clutchplate he ordered was made of masticated riceballs. It happens.
Unless something has changed in the last few years at the factory, I wonder what the service advisor would say if you advised them that Subaru does not even make their own clutch assemblies, just like many other items on those cars.
The clutch maker used to be Atsugi so one could make the point that Subarus come from the factory with aftermarket clutch assemblies, just like every other car.