757 For what it's worth my 2 cents.
I have a Para Limited (Stainless) and STI Edge (Blue in 40 cal). The difference? The para is a gun that you have to spend $$$ on to get to the same level that the Edge comes out of the box.
The Para comes from the factory with some side to side slide movement and will loosen up pretty quickly , the Edge has no dicernable side to side play in the slide and I've had 7-8K rounds through mine and it's just started to have a small amount of play in the slide - still less than the Para out of the box mind you.
A more crucial area is the vertical lock up at the back of the barrel which has a big effect on accuracy - the stock Para barrel will shift noticably under thumb pressure. The STI has no discernable play even after all the use mine has had.
The Para hammer is milled in a interesting way - I assume to reduce costs. But if you are going to do a trigger job you junk it and buy a 'proper' one. That's another $60 before you start. The STI internals are all top notch. It comes out of the box with a 3.5lb pull. The 'tuned' variants will have had this cleaned up a bit too ;-)
To sum up - Para Limited, trigger job, new Clark custom match barrel and FO front sight = same cost as STI edge out of the box.
Having said that my Para is as good as the STI from an accuracy and trigger pull perspective, (everywhere apart from slide fit) but I brought the STI anyways. Para's have cheaper mags (mine are all-steel Pro-Mags, cheaper than Para factory mags and one-piece steel bodies).
Given the choice when I leave for the range I pick the STI, it really is a great piece of engineering - anyone want to buy a Para Limited??
;-)