what is the difference between the original and the gen 11?

The original XTR was made in the USA. It was okay, for what it was. However with the second gen, they incorporated several new features like;
FFP
Illumination
Exposed Turrets
More internal adjustment
Improved lens coatings
Made in the Philippines (keeping the cost down)

These are great scopes for the money.

Skylar sure know his -hit

found 1st gen,(nib $600.) illuminated, 30mm, comparing to the 11, did see much different other than the price,

Idk if you're looking for mil or MOA, but 1st gen had 8 mil per rev and 2nd gen is 10 mil per rev...

I love my XTRii a lot granted I just got started shooting longer ranges. My dad prefers the SWFA HD as the reticle is easier for him to see as it is .5mil windage adjustments instead of the .2mil adjustments the XTRii features. I do now know if the first gen has zero stop but that is an awesome feature on the second gens.

You have the SCR reticle with .2 mil holds, my XTR II has the G2B reticle which only has .5 mil hashes.

I would rather have the G2b honestly but the SCR I can read and it works. If it isn't broke...

I am pretty easily satisfied, just ask my wife

I just bought an XTR II in 5-25 and put it on a Tikka T3X Varmint. Total disappointment in the image quality. The image isn't particularly crisp in the center, and it really loses sharpness out towards the edges. I have a Nightforce SHV that's in the same price range as the Burris, and there's no comparison between the two on optical quality. I really like the features on the Burris and the SCR reticle is excellent for long range shooting, but the glass, at least on mine, just plain sucks.