It is my understanding that they are heavy.
I hear that they are best suited, in .308, for FALs.
The again, I've never actually seen one.

They are good as collectables, but there are better alternatives if you don't acquire stuff based on hisorical merit.

Commonwealth countries and Isreal used them, but they are no longer used (hint, hint, they're obsolete).  The Izzys are calibrated for 5.56 whereas the Commonwealth ones are for 7.62*51.  This calibration was simply accounted for in the external adjustment cam that the whole thing sits on, so in fact the optics are the same.  I have also notices that the installation spring has a horseshoe shape on the Izzies, and a Zig-Zag shape on the Commonwealth ones.

The general thought on them is that the Commonewalth ones are better, because of a better spring, and less use.

Always keep in mind that you need a T Bar interface mount to use one at all.  

I luv mine! Its great. Easy target acquiwhatever. Low light time I remove the eye relief. it just seems great it took me a while to zero it in I had to start on the 3 meter range and work to 100 meter. I have and M4gerywith a 11.5 barrel and subsquent flash hider. My rifle will nail the same spot every damn time I point it.
It was the best 170 I have ever spent on any optic.
I removed my trijicon for it. and dont regret it one bit.
Yes it is heavy but I couldnt give a damn I am 6ft and 215 (marine corp) what the hell is a pound or two.

I saw some Israeli surplus ones that M&A Parts was selling at a show recently, first time I've been able to examine one.

I was very impressed with the optical quality and liked the vertical post that comes down from the top.  They were selling post illuminators for about $25 but it wasn't hard to see it w/o one.  I viewed some dark corners of the exhibition hall and thought the low light performance looked decent too.  External finish wasn't great but you wouldn't worry about scratching or scuffing one.  I didn't notice a lot of weight.

I think they'd be a good choice for a carbine but don't know what the mounting options would be.

I have an Israeli unit on a Trijicon TA 52  base for either FAL flattop or AR flattop. Lighted reticle with Entreprise Arms Second Generation light.Nice shape.$225.00.The only differance that I can see in a English versus Israeli is an identification tag in Hebrew, which is kind of neat.