I have been using an sk350 this past summer and couldn't imagine working without it. I did alot of research on specs of the different brands and the Ditch Witch seemed like the best bang for the buck, but I haven't used any others so my knowledge is limited there. Hopping on and off the machine with ease is incredibly valuable, however it does move slow compared to the small full cab machines, which is making me seriously consider upgrading to a PT30.
What I've found works extremely good with the sk350 is just using it to load wheelbarrows. The machine moves about the same speed as a wheelbarrower, but I can have 3-5 cheap labourers running wheelbarrows that get insta-filled, equalling the speed of 3-5 sk350's hauling loads to their destination (one sk350 bucketfull = one full wheelbarrow). They can also access anything regardless of fence's and tight areas, and work in very wet muddy conditions by laying down a path of plywood planks. Made some pretty good coin this summer with this technique.