802.3ab 1000BASE-T works over all of the most common Ethernet cables and structured wiring I've thrown at it, even wiring that probably fails to meet even the loose Cat5 spec.
I've not had any experiences being made crazy by it in the last decade. Some of the very old gear had interoperability issues, wouldn't auto-negotiate, etc, but that's often the case on any new "standard" tech. Nowadays, you can take the random $15 adapter, $2 cable, and $20 switch and expect it's all going to "just work" at gigabit speeds.
