I believe there is a program you can use to pick up the Wii U Pro's Bluetooth signal on your PC. It functions as a keyboard mapping replacement though, so it might be 8-directional input.
Anyway, I have an absurd amount of controllers at my place- 2 Wii Pros, 1 Wii Pro with a GCN shell (awesome feel, actually, it's one of HORI's new ones), a Smash Bros. GCN, a Wii U Pro and the Gamepad. While the Wii U Pro is amazing and super comfortable, I play off-TV too much and rarely use it except when playing pretty seriously, like in Hyrule Warriors, MK8, and some other titles.