I've seen a couple different ones, I've seen an ultralight one that has a flange machined into the back edge so you don't need the big guide washer.
 then of course there's the findenza adjustable. I have seen them on some sights as being different degrees for different colors.  3 degrees for silver, 6 for blue, etc.  I thought they were all the same range, but perhaps not.
 What do you guys use and recommend?

I know, that's what confused me about the place selling the different colored fidanzas. they are all slotted with infinite adjustment. But they listed the colors with different degrees. I thought maybe it was the +- range of he particular sprocket.
 So, was it a messed up site selling it, or are all the fidanza adjustables the same? I can't even find the site that listed the degree differences for each color.
 anyway what would be better , the lightweight one http://www.speedwaymotors.com/Ultra-Light-23L-Ford-Square-Tooth-Adjustable-Cam-Sprocket,32338.html?utm_medium=CSE&utm_source=CSEGoogle&utm_campaign=CSEGOOGLE&CAWELAID=1549156538&CAGPSPN=pla&catargetid=530009170000006315&cadevice=c&gclid=CP6x1J2N3L0CFeZDMgodQmwARQ
or the fidanza  http://autoplicity.com/products/39251-fidanza_986234.aspx

awesome, thanks amc :]

I was looking at those, the savings is definitely nice. I'm just thinking it might be worth the extra to not have to loosen the belt and remove the cam gear every time I want to make an adjustment.