I've got a client with a 70 person network - Exchange, AutoCAD, Databases,
etc. The work with high res pictures but according to MRTG, there isn't too
much requested from the servers except at times when printing or pulling
down files.

I've got a Gigabit switch on the server cabinet
And a mix of Gigabit connections from the desktops as well as 100 Mbps
connections.
This is because I have a Gigabit switch connecting runs of which some have
100 Mbps switches for more desktops and some have straight runs from the
desktops. It's because there are limited runs from workstatoin areas.

My question is... Is it better to put all workstatoins at 100 Mbps, should I
make them all have Gigabit connections, or should I just keep the mix and
not worry.

What's the best practice?