They probably didn't bother checking to see if they actually "fixed" them.
Sort of like the problem I had with my old iPod - I had to send it into repair (to the wonderful BestBuy repair folks) since it suddenly stopped holding charge. They replaced the battery, considered it "fixed" without checking to see if the battery was the problem (it wasn't).
Mine was built by thrice (Rockhopper Audio). Depending on my audio finance situation, it may be undergoing some changes to it in the future, but it's still a maybe at this point.
The big issue I had with RPX-33 when I tried it was it just didn't have enough power. For every cans I tried with it (Grados, K701, K1000, and couple of others), it just seemed like it was straining to drive them. While many headphone amp can't do this, but it really couldn't drive K1000's at al, IIRC.
I'm surprised I've actually heard four of the listed amps, two of them I own/owned. Yes, I do really like my ?22.
On a side note, RPX-33 was spectacularly mediocre when I tried it in the past.
Hope you don't have to stay late at work, Nate.
Yeah, I'm under some delusion that once I buy a house, I'll have my weekends back, even though I'm well aware I'll most likely be doing stuff to it on weekends (e.g., painting, cleaning, etc).
Good to know there are folks here who have big head. It's a good thing I keep my hair real short, otherwise, I've a feeling I won't be able to wear most headphone comfortably.