Hi;
I have found this thread rather interesting since when I get antennas up 
next spring I will have a similar choice.  I may be incorrect but after you 
add two filters and the microphone adaptor there isn't as big a price 
difference as there was between the two rigs.  I think I once decided it was 
about $400.00
My real considerations would be the quality of the hf receiver and whether I 
want hf uhf and vhf all in one radio?  Since many folks may al ready own a 2 
meter radio they may or may not want to duplicate things.
From what I have been told I'm not certain the increased accessibility is a 
real concern.  The fact that I hear a number for the mike gain setting is a 
nice convenience but counting worked well with the 570.
Richard