I have fired both rifles, though I have fired the M14/M305 much more than the M1 Garand.
I like the M14 more. Everything I have decided is based on my personal experiences and opinions obviously.
It feels more reliable. The feeding system is much more reliable. The internal pieces when dissassembled are much simpler in the M14 (compared to the jigsaw puzzle of tiny pieces that make up the op rod and cartridge feeding system in the M1)
I find the M14 easier to control, shoulder and handle.
As cool and "iconic" as the enblocs are when they make that "ping" sound, they are a pain in the ass in my opinion when compared to the simplicity and reliability of a loaded magazine. Or speed feeding clips down into the mag with the action to the rear.
The only thing I think the Garand has going for it, under which the M14 lacks in my opinion, is the venerable full powered .30-06 cartridge and the aura of nostalgia surrounding it.
They are both awesome rifles but my hat is off to the M14.