The original Tugeye for Royalex boats is indeed easy to install. The newer version for kevlar is more difficult/awkward - that comes with a little tube/ring whatever that kept falling off when I was pounding it home.  Of course, once it fell off, it rolled somewhere in the garage and I had to hunt it down - luckily, I found it hiding under the truck.  take care with that.

Its a whole lot easier, pretty simple, to drill the royalex boat; the UL kevlar was more difficult, as its a thin, flexible surface and the resin tends to chip, not cut - putting a piece of masking tape on where I drilled helped a bit with that.

The royalex version has an inside diameter of about 1/2", or maybe 5/8" (don't have a canoe handy to look at) which makes it easy to run a line through - I use cheapo floating poly line from Home Depot - it looks like kernmantle climbing rope (its not that yellow crap - this has a good "hand" and knotability), but I don't suppose its more then 300Lbs tensile strength - not gonna winch a canoe off a rock with it, but fine for painter use.  Don't need to do any lining in Quetico.

The kevlar version is smaller, with an inside diameter of about 3/8" and won't take the bigger diameter rope.  I only installed one Tugeye in my UL boat so far, in my Northstar, but will get around to putting one in my Merlin.  I don't worry about the carry handle not working for a painter line attachment - the reason I installed the tugey in the kevlar boat was to be able to lock it to my rack, which locks to my truck (I run a cable thru the frame and rack and the canoe is attached to that) - or to lock it to anything else, to add one small deterrent to keep someone from just walking up at night and cutting a couple of ropes and making off with three thousand dollars worth of boat - at least this way, they need a bolt cutter with them to cut the cables.  That's one thing I don't like about the smaller tugeye for kevlar - I can't find a "good" cable lock that will fit thru the small hole - I could only find a cheap bike lock with a 1/4" diameter cable that will work, but at least its somehting.  The royalex version, with a larger diameter, I use a kevlar reinforced bike lock that's about 3/8" diameter - had to file off a flange at the end, but that didnt' affect the cable strength.  One trip last year, I had to leave my Rx boat unattended at the put-in while doing a shuttle - it was nice to be able to lock it there.  

It may be rare, but boats do get stolen - I seem to read about two or three each year on P-net or C-Boats.  Last time, as I recall, a paddler left his boat at a takeout along a highway while he went back for his vehicle - somehting he'd done several times before at that same spot - this time, boat was gone when he got back.  Here in Colorado, there are always a few kayaks stolen in similar circumstances each year.  

So for me, installing the tugeyes is more about having a bit of insurance, being able to lock my boats, than it is about lining or anything else.  They work fine for that.