Hey Rojoyinc, they are AWESOME.
Nothing short of a small miracle for beach cats. Time and time again I've read how much folks value them. I've had a set for ~2 years and they absolutely save me and my aching back. Not to mention my wife's when I get her help. Whenever a neighbor or beach comber walks by and spies me using them I always get the "gee, those sure are neat, sure do make it easy sonnyboy" type comments.
You can definitely use them alone. I do all the time to get my boat from it's resting place ~50 yards from the water and back again, and then ~100 yards to the house for cleaning and maintenance or to put it on the trailer.
That last benefit was an unknown until I tried it and it's great b/c you can roll your boat right up onto and off of your trailer (using stern pads, of course) with the trax. Nice. You gotta ask yourself how you're going to get her to the drink when you go to a nice new spot without a ramp. And think about how many more sailing opportunities that opens up.
Here are mine being trailered:
http://sphotos.ak.fbcdn.net/hphotos-ak- ... 1325_n.jpgThey will also last and last. One post I read was from a guy in southern Florida who claims to have left his in the dunes for something like 20+ years, using them often and in the salt water and never rinsing them, and only recently had to replace the tires because they finally dry rotted and gave out.
The up front investment is a difficult pill for everyone to swallow but I have yet to come across anyone who says it wasn't worth it. Much to the contrary in fact, most say it's one of the best investments they've made due to the sheer ease with which they make portages, the longevity of their solid performance, and the protection they bring to your boat while moving her. A truly high value when the cost is spread over their long lifetime.
Do yourself a favor.....