re: Keel Easy
The 'pros' have been noted, though I think (having applied Keel Easy a couple of times to commercial boats) that folks are being too modest when stating that it is 'easy to apply' - it's difficult to get it perfectly straight along the keel line, and working around skeg slots is tricky. Also, if the bow/stern have sharp upsweeps in the keel line it takes some work with a hot air gun (and thick gloves) to get the KeelEasy to conform without wrinkles. And, using hot air around a varnished boat takes care.
Probably all this would be easier in a warm climate than it was here in BC - though that wouldn't explain Et's success, so it must be skill!
:-)

KeelEasy 'cons' from my paddling group:
1) Expensive (extremely, depending on your 'cheapness') - $100 CAD plus for a 16' kayak.
2) Not slippery - if you are in the habit of paddling your boat up on to underwater rock shelves and smooth boulders through inattention, and then sliding off again- that won't happen with that KeelEasy strip on the boat.
3) It will peel up if scraped on a rock -so it's best to make the strip full-length if you plan to apply it to the stern. BTW, though it depends on the keel shape (rocker, sharp vs round-bottom) the stern (not bow) gets most of the abrasion if the boat gets pulled up on shore, especially with a load of gear/water inside...so that's where the strip will do the most good.

BTW, if you are in my area, I can sell you a couple of lengths of (white) KeelEasy. :-)