I have the exact same car as you and yes it made a difference you can feel where your ass meets the seat. A good part about it is WHEN (not if) you get gears, new wheels/tires, you can calibrate your speedo with it. There's a lot of play with the electronics you can do with it. I got mine on ebay for like $320 shipped. HOWEVER!!!! if you have about $250 MORE $$$$$ I would get a custom internet tune from Tim Barth at modularfordpowerhouse . this guy knows his ****! I think his tunes are in the $500 range.
22* sounds like a lot of timing, i'm running 15* and thought you shouldnt really go over 16* , or is 22 just the setting on the predator which equals like 16*? An extra 250 for an internet tune I thought they were about 100.