As you are aware there are pro's and con's to all three. I have ridden Campy for the past decade plus. Not as light as SRAM, but for my size, it doesn't matter much. The biggest knock on Campy is that it is not as easy to replace parts when needed as many bike shops just don't carry them due to lack of need. The good news is that Campy friggin lasts a long time.
Shimano is a slight notch down in my opinion, but not that far off. It is the most common and thus easy replacement of parts. I am not a fan of their shifting. Though that is a personal preference thing.
SRAM I have not used personally, I have heard mostly good from those that use SRAM components... that said, not good enough to get me to consider switching.