On the whole I don't see any big differences in the skills between euro and 'merican refs. You can hand-pick top examples from each country and have a great crew, or you can take whoever shows up and have a crap crew.
The big difference (to me) is the way the reffing is handled between the different series: NPPL - dedicated judges, PSP, Millenium - team judging. Dedicated judges don't necessarily gaurantee better judging, but it does eliminate favoritism and, in the long run, should provide more uniform judging.
As far as the stand up/lay down issue - good referees move around as they need to, with starting positions and coverage zones based on the field layout. Positioning (laying, standing, missionary) only takes you so far. If you're not willing to get in there and take the hits, you can't make the calls and you're a crap ref.
Don't get me started on the french...
PS - Scut, clean out your inbox. I tried to respond but your box is full.