What kind of MacBook did you use, and did you plug it in to an external display?
My 2013 15" MacBook Pro is extremely loud when plugged in to one or more external displays. Seems to be related to the fact that its fans are either off, or at 100%. Or at least have a very late, aggressive curve. It's also very loud when the CPU is constantly pegged at 20% or more, which is basically a given when running Xcode.
I can offload some things to the cloud, but I can't offload my UI and local apps, which are the things that cause the really loud noise.
When it's under a light load, it's very quiet - moreso than most non-Apple machines I've used. But under heavy load, a number of other machines seem to be much better at expelling their heat without sounding like a jet engine.
