Jason,
Really great work - all of it. Sorry the client issues - because they should definitely be telling you this!
Don't worry about the bake time - I think the grain adds to the effect. The linework balance is a delicate thing - you just have to play with it till it looks rightg to you. One other suggestion would be to export some shadows in one of your sketchup views so you can overlay them and add just a little more depth to the lower end(nomally darker areas)shadows. Maxweel seems to highlight nice depth at the higher end, but balances out the low end a little IMO.
Thanks for the inspiration! 
Bytor