Both sets have their problems.
The definitive is CAV, which means there is less video noise (The SNR is up to 3DB better than the CLV version), typically less crosstalk, and better image stability, and better colour stability. It also allows you to do slowmo and still frames if you are using almost any laserdisc player.
The NTSC transfer itself has some problems, split sabres on some frames, some edge jaggies on others and some 'trails' as a result of a 'virtual' dirt removing algorithm that didn't work so great.
Being CAV it is more discs, so more side changes to deal with, and some DEF editions had some missing footage.

The US faces set is CLV, so a little more video noise, image stability- especially edge stability is noticably worse (but can be fixed with an external TBC in most cases) and crosstalk is evident on most players.
It is a better transfer in some respects, no split sabres, better edges in some scenes, none of the dodgy trails, but introduces some artifacts of its own, e.g. beter colour in a lot ofd scenes, but worse colour stability and a noisier chroma signal. Being CLV there are less side changes to worry about.

The Japanese Faces set however seems to be the same transfer as the US definitive set (albeit with a different black level) as it also has the split sabre problems.

Some of the above issues may or may not be visible depending on the quality of the player you have.

The DEF edition also supposedly is more susceptible to rot, but both my DEF sets are rot free.
This is not the only differences by a long shot- but the ones that I care about at the moment.
That is why we are using both sets to create our master.

thank you very much Laserman for that explanation,and ALL my Star Wars Ld's are fine too,no laser rot,i dont know how good my player is but i dont know how to do all that filtering,so i will probably do my Faces set.
my player is a RCA Home Theater Series LDR400 do you know how good or bad this is?
thanks again for the response
darkjedi

Mainly 'cause we are kinda busy, and that question isn't even 24hrs old yet. ;^P

All NTSC letterbox (non anamorphic) suffers a little from jaggies on lines that are just off the horizontal - it is purely a function of the reduced resolution available, however they are nowhere near as bad as the pictures posted here.
There is little difference between the faces and definitives in this regard, though the faces are *slightly* better.
The pics that were posted here of Leia in the war room had excessive sharpening, and a low dynamic range which made the problem look much worse than it actually is.
On the PAL set you get less jaggies in general because of the extra resolution, and the tighter framing i.e. it is 'zoomed in' more, so you lose some picture, (pan and scan 'lite') but what is on screen is bigger, so more scanlines to go around.
Short answer - they look good on our transfer - I'll do some pics over the weekend to show what I mean.

Very interesting - I had not checked by face versions wrt double sabres - I was doing the DC versions only.

This sounds like a good project for a wet weekend

Does it also have ghosting in the Luke vs Vader battle is ESB? What about ANH, anything in there?
From memory there was some when Greedos head thunks forward onto the table, but my brain could be plaing tricks on me...