I got mine first, and got the CycleOps Fluid, love it.
my husband got his second, and got a kurt kinetic fluid. I have never ridden his, and I don't think he's ridden mine so we don't have input there.

His was a little less expensive and looks well made. The Kurt adjusts by turning the two sides, whereas the Ops has a bolt like thing you tighten down.
The quality of both seems solid. The Ops flywheel and cooler vent is a little heavier.

Here is a quick side by side picture of them (not super quality).

http://farm3.static.flickr.com/2050/...57636b61_o.jpg

I should add that mags are cheaper yet, but the ride quality is said to be less pleasant. I like that we do not have to do anything other than change gearing for resistance.