Yes, my 50 lux (f1.4) is quite nice on the G1 and the MF makes them so useable. But like you having the 20 (f1.7) with AF will be great.
I know I'll love the AF when it comes in the 1.7/20 but for the moment I'm in love with the following c-mounts:
-Schneider Cinegon 1.8/10mm (black tube)
-Schneider Xenon 1.4/16mm (black tube)
-Schneider Xenoplan 1.9/25mm
-Angenieux (B&H version) 0.95/25mm
-Schneider Cinegon 2/50mm
They are all really awesome one stop shy of wide open and very 'stylish' wide open! I'm getting very quick with the zoom focus on the G1 as practice builds... The GH1 can't come soon enough!
Speaking of psudo-macro... The Cinegon 1.8/10mm focuses to about 3-4 inches!