I bit the bullet and got the spectrapure for my set up. Havent' looked up the $120 deal, but much better than what I paid. I got great customer service too. Somehow during shipping or packing two of the housings were scraped up and they sent 2 new ones right away. I don't have experiece with the other restrictor valves, but did go through the adjustment process on the capilary flow restictor. Seemed a little technical at first, but it was pretty easy. Just a little time consuming. I think it took me about 1/2 to get it dialed because I didn't want to over trim my corrections.
Bottom line I have been happy so far.
Good luck!