We have a multi project solution that I build on Windows.
It's quite big but it does build reasonably quickly when done from local files (a minute or so).
However I have noticed that it takes orders of magnitude slower (>20 minute builds) when built over a Samba share. It appears to take forever on the _LinkAssemblies task when outputting the list of resolved assemblies.
Perhaps there's an obvious optimisation that can be done here? Perhaps not.
It's not a show stopper, just a bit inconvenient as I'd prefer to kick off cross platform builds from a common location, but I thought I'd mention it here anyway.