I have a 11' switch rod that I almost always use spey casts with.
I have found spey casts to be very liberating. The few times that I used my 9'6" single-hand 8 wt this fall I always used a spey cast when I was up against the bank. That rod is a Winston BIIx and usually has a SA steelhead taper on it. Even being a relative newbie to spey, it has changed the way I approach pools, banks, etc. and has opened up more water to me. At least for me, spey casting is not about longer casts but covering water more effectively.