My blast tamer arrived yesterday fitted it in about 5 minutes and it's great no idea on performance yet but it sounds and feels much better no fart noise and the twang has gone.
So it's worth it just for that to me anything else is a bonus.
Big thanks Steve just the ticket.
To the post above you just need to study the photo on about page 3 of this post take the stock off then unscrew the threaded bolt that holds the stock on, slide the wire through, poke the bent bit through the trigger block behind the rounded knob thing that flys back and forward when you fire. Screw the bolt back on, slide spring on then little block compress the spring a bit tighten up Allen grub screws stock back on bobs your unkle, fanny s your aunt.