Retractable tracking keel on PA

This seems like a pretty sweet addition. I've never been in a Pro Angler. From what I've read on here it sounds like their increased stability is at the cost of some tracking ability. Have these been featured on any other kayaks you guys know of? Do you think it will bring a noticeable improvement?

A keel, like a rudder adds drag, more drag reduces speed, and increases effort to move it.  If you were using a sail it would'n't matter, if you were using your legs or arms I would think you would notice how much  longer it takes for you to move your boat.