To be frank, the fglrx drivers, nowadays, are not harder to install and get working than the nvidia drivers.
As for Open source drivers, I do not care all that much about that, as long as the drivers are working properly with up to par performance.
As long as I can remember, the original Radeon, Radeon SE, Rage 128 and even the mach32 and 64, I always managed to get the ati cards to work correctly and with good performance in linux.
Like it is now, it is cheaper to get an nvidia card than an ATI card for the same level of performance in linux. I am tired of funding a company, ehich doesn't care all that much about it's linux users, for the sole reason that this company is Canadian like I am, which btw is not the case anymore. Now I want to support companies which really support linux, nvidia for their good linux support and Intel for their open source drivers and their excellent programming tools (compiles, profilers, optimizers and debugging tools).