I have been interested in one of these since seeing one at a gun show last year. Right now I can use my G19 gen 3 when I want to shoot it, or take the Glock out and carry if I wish. I will be looking for a good deal on a used Glock to keep it with the conversion kit. Yesterday morning I happened to stumble on a sale at OpticsPlanet. $169 for the MCK. I know their service can be hit or miss. I ordered the MCK, flashlight, and thumb rests. 5 minutes after ordering, I saw Primary Arms also had a sale. The kit was a little more but the accessories were cheaper. The shipping cost was the only difference, which I would have been ok with since I trust Primary more than OP. Anyway, I got my shipping confirmation today. Just checked and OP is up to $230 and Primary is out of stock. OP still has the Sig version for $169. Guess I lucked out all around!