I have this weird thing when playing games on consoles that have been "rebranded" midway through their life cycle.
A perfect example is with the MegaDrive. With the Model 1, I prefer to play all my Black box games, as that was how it was being marketed at the time. But then the Model 2 came out, and they changed all the art of the Red label games. It doesn't feel right playing my black label games on the Model 2. Though for some reason I have no qualms with playing the red label games on a Model 1.
The PS3 is another good one. If a game was released before the slim, I'd prefer to play it on the original PS3 fat. Though again no issues with the "PS3" branded games on a fat, it just feels weird playing the early titles on a Slim. Same goes for the PS2 and it's re-design in 2004.
It gets to the point sometimes, that I will completely avoid certain titles on my shelf. For awhile, I had my Model 2 MegaDrive hooked up, and I barely even touched my black box games. Since getting my PS3 Slim a couple weeks ago, I've noticed I've been avoiding my launch titles and other pre-slim titles a bit, as I would very much prefer to play them on my now dead 20GB (And I really want to replay MGS4....).
I'm sure this sounds very odd, but I just wanted to get this out there to see if I'm not the only one.