Two more points:

Though I'm not a great believer in the "work on a laptop
in Starbucks" concept, I'm strongly in favor of being
able to work *from* a laptop wherever you are - using
a remote desktop like vnc over ssh (or whatever variant
on that idea you prefer).

Second, there's a trade-off to be made between the effort
put into making builds go fast, and the total time spent
by all developers waiting for slow builds. If you're
planning to have hundreds or even thousands of developers,
as for the Linux kernel, then it's good to spend a lot of
effort making builds go fast (and use compute resources
efficiently); if you have 20-50 developers, then it may
make more sense to spend $20K on a compile farm rather
than say 2 man-years on making single-machine builds go
fast. Horses for courses.