Just ordered 2 from Ruger at less than ebay pricing plus free shipping. I'll give one to Son and use the other for an upgrade for my "possum on the porch" pistol.
I do like the low height vs using a Weaver base and clamp on dot interface.
I'm hoping the "footprint" of a 2nd hand Primary Arms dot I already have matches the base. It may be a while before I can fund another FF3 since I just got a "deal" on a couple of Vortex Crossfire II 2-7x32 BDC riflescopes.