Thanks for your speedy replies - very useful to have experienced insight.
I think the big cart pictured above is a behemoth and will definitely prove the most effective for my needs. My concern is the size and price. I would like the option of taking one of these carts with me on the TI for getting up the next deserted (hopefully) beach I come across. I am looking for that perfect piece of equipment that does almost what the big cart does, but is also useful for trips in the boat.
I appreciate the mention of concern for the plug in carts. I did buy the recommended accessory for the plug in (a 6 inch wide piece of molded fiberglass or plastic that sits on the base of the plug ins to provide better weight dispersion. That was a very important piece.
In your opinion, would the hobie Trax (plug in) offer significant gains from my current heavy duty plug cart or should I go with the behemoth you have both mentioned? Can it be easily disassembled and tied to the trampolines for the next beach?
Do you think that something like what wheeleez offers a reasonable compromise between the two? It is not a plug in (which I assume has some advantages and disadvantages, but it looks like it could work for a TI and does seem to fold up rather nicely if transport on the boat needs to be an option. Has anyone used this cart or a cart like it? In the opinions of others, is this a superior or inferior.
Here is the Wheeleez cart: http://www.wheeleez.com/kayak-cart-beach.ph
Any other words of wisdom would be appreciated.