Trail Trecker Kayak Cart

Saw this kayak cart surfing on the web today. Might be something worth checking into. Check out the video!
http://paddlelogic.com/trailtreker-kayak-carts.html

I'd want to see it going through the sand...

if you don't live near sand or mud it'l be OK
if you do.....then NO

Without balloon tires, it will not support your kayak in soft sand, and, should you have a mass of gear and abs and a stringer o fish, the wheels so far at the back will prove impractical and the front end will be too heavy - other than that it's great! 

It looks to work well with light yaks and light gear on a trail over 4x4s

waste of money here.

Without balloon tires, it will not support your kayak in soft sand, and, should you have a mass of gear and abs and a stringer o fish, the wheels so far at the back will prove impractical and the front end will be too heavy -

Yep.

Since the kart is at the end of your kayak it will be pretty heavy since you will be holding up all the weight. With the Rolleez you can balance it.