I have a Clicgear 3.0 that I purchased used for $130, and I like it a lot. I probably wouldn't buy one new as they're pretty expensive, and aren't really intended for disc golf. For the price of a new one you could probably get a dedicated disc golf cart. That said, the Clicgear is well built from what I can tell, and the only part that I have any doubt about is the main folding hinge just below the handle. It has a little more flex than I'd like, but doesn't show any sign of cracking. I'd prefer the part be made of metal, but I'm sure that would only add to the cost. The wheels are great in the mud and grass, and I don't have to worry about them going flat on the course. The front wheel is fixed, and has a locking mechanism which works well for most hills that are less than about 30 degrees. Any more than that and the front wheel can start to slide.
I use mine with the new Voodoo Spinal Tap, and while I haven't modified either bag or cart, they work pretty well together. I tighten up the shoulder straps on the bag, sling it over the top extendable golf bag holder arms on the Clicgear, and then secure the bag's sternum strap around the underside of the cart. The bag is fairly secure that way, but can come loose if you're bouncing over really rough terrain. I've played some tournament rounds in heavy rain and the setup was really nice to have. I don't use the cart every time I play because the courses I frequent just don't need it. However, for long tournament rounds it's great to have!
Eventually I plan to create a horizontal shelf that sits atop the lower golf bag arms on the Clicgear to support the bottom of the bag, and take some load off of the straps. Unfortunately I haven't had the time to do it just yet.
I've included a crappy pic of the setup below, and I'd be happy to take more pictures if you're interested. Just let me know.