I have a GFB Respons and can't fault it... well made, fully adjustable to full VTA or full recirc and the spring tension just takes an allen key to adjust
But... it's expensive... SWMBO bought it for my birthday though
Also +1 for Forge, had one before and their after sales support is superb - they sent me a free full servicing kit for a Forge valve I bought off ebay!
J.