Just found this:
http://github.hubspot.com/BuckyClient/
It claims to use a tiny Javascript include on any web page to provide detailed reports of loading speed, straight from actual users.
Could be tremendously handy for lander and redirect speed profiling. I haven't tested it yet, but will report back when I do.
It's not exactly user-friendly right now, though - will definitely need some coding to make it usable.
I think New Relic offers something similar on its free plan.
Yeah, I must get around to testing the NewRelic service. Thanks for the tip!