I (very happily) use an Onkyo 5509 pre-pro in my (very elaborate) 2 channel, music only system, FWIW.
There's an interesting situation that arises when/if your 2 channel, music listening involves subwoofers. To my ear, the bass management/room EQ capabilities in this circumstance tend to outweigh the "purist" circuitry of high-end pre-pros. I own the Onkyo and a Theta Casablanca (original) and, tho the Theta sounds great as an analog pre with a traditional stereo set-up, I much prefer the Onkyo for 2.2 listening. I also prefer the Onyo to my ARC LS 25 and my Joule line amp for 2.2 use.
So, if the subs are on-line for music, I'm happy with a good Audyssey xt-32 enabled pre-pro like my Onkyo.
If I were disabling the subs for two channel, I might re-think my priorities and go with (or, at least listen hard to) one of the high end manufacturer's products.