I, too, am using '78 Cornwalls for the fronts (in fact I bought them during the blizzard of '79 - this weekend brought back memories). I'm using Heresys for the surrounds and a C-7 for the center. I love the sound I get using the 950 and a Parasound amp - thinking about the new 7100 if I get wife approval. I've never thought about changing speakers. I did perform a minor "tweak" to the Cornwalls and have thought about upgrading the crossovers to the AKL versions. I have listened to the newer Klipsch speakers but preferred mine. One thing to consider though if you decide to go for older Klipsch models is space. They take up a lot of room.

Don