They were pretty easy to install - had to file down the pin on the lever that holds the buffer cover on (yeah, I'm sure my terms are wrong). So there may be a way to not have to do that, but I'm not savvy enough - so i would have to buy a replacement part if i wanted it to be a stock SKS again.
I really like them, the longer site picture is GREAT.
I always think its weird how buy direct from the MFG costs more than a lot of other online stores... Maybe they need to keep that MSRP up - but you would think they would want to sell as many direct as possible.
Have a set on my Russian SKS. Work Great. there are enough set screws to secure the rear sight in place it will take a lot of recoil to loosen them up. Little lok tite helps though.
Installation was pretty easy. like others said file down the pin in the rear and easy done. I removed my OEM rear sight to keep line of sight clear.
Had it on an SKS years ago and loved it. Probably the best upgrade to the SKS IMHO. Gives you a sight picture like and AR or M1 and really allows the gun to shoot more accurately because of the improve sighting system.