Thanks folks. That's about what I was thinking. I had read that crosstalk is better on Cat6 but I don't know how much effect that would have. I suspect there are plenty of other bottlenecks on their old equipment that would need to be addressed before the wiring becomes the factor.

I will say that it doesn't seem like the nicest wire, TBH. And I do wonder what the MHz rating is. That's not something I've paid much attention to in the past.