As far as the 5800 els, its a fine machine but the clamps are not as nice as the counterpart 8800 els clamps. The 5800 also uses their lower end non self centering mounting system.
Just to expand on this. The 8800 offers more bells & whistles and cuts down time to mount a rqt.
1) The electronics have the telephone keypad to enter tensions.
2) The 6pt mounting system on the 8800 is the suspension mt. sys., you turn one knob and both shoulder supports come in simultaneously. the 5800 has the quick mount and you have to adjust each arm individually.
3) The 8800 has the self-centering turntable. the 5800 base model does not but in April 2010 you'll be able to upgrade the 5800 w/ to an SC TT w/ quick mount.
4) The base clamps are different. the 8800 have a cam & are easier to lock & unlock. The 5800 has quick action clamps which are pretty much a nut & bolt that looks to the TT. they are both very reliable.
if you need any other specific info about the machines let me know.
bret