Elka shocks are made in Canada. The build is as good as any high end shock out there. They are so nice, it's a shame to have to hide them in the bike. They get very good reviews. I had one in my hands at the bike show in Toronto last year and came within a hairs breath of buying it. Buying and upgrading a track only RC kind of emptied the bank account last year and therefore had a hard time justifying spending another $ 1000.00 + when I just picked up a used Fox!
The stage 4 has ride height, rebound, high and low speed compression dampening. If you buy one, have it sprung and valved for your weight, riding style etc.
They also have fork piston kits. My front had one installed by the previous owner and it feels very good on track. Hard to compare since I bought the bike with it already installed. It came with a stock shock with a Elka revalve/piston but I never rode it. I opted for a used Fox instead. Turns out, the compression dampener adjuster is f....ked and will therefore install the stocker w/Elka valving this winter and give it a go at the track next year. If that doesn't work out, I will not hesitate to buy the Elka shock, however without ride height adjsutment.