We're using a GBC Titan 110, which is a 43" heated roller model. It works well enough, but all the safety functions tend to drive us crazy. If you don't have the feed tray set properly, for example, the thing won't feed. That means you have to have the feed tray installed to clean the bottom roller, since you can't turn that one freely by hand, and having the feed tray installed means you have to get down on your ass and work looking back up into the machine. Also, the sensor doesn't work smoothly, which means a lot of reseating of the feed tray in order to get the thing to feed at all. Then, to get the thing to just feed without the foot peddle requires a plexi shield be in place. The middle of the machine between the two sets of rollers is also very cluttered, making it difficult to clear out jams.
When it comes time to replace it I'm thinking seriously about a D&K Exp 42 Plus. I saw the Exp 62 Plus at Graph Expo and was very impressed. It doesn't have any of those nasty safety precautions, but unfortunately doesn't have the emergency stops, either. It's a little less cluttered in the middle, which is nice. And finally, the rollers are heated directly, rather than having a glass rod in the middle which then heats the roller through the air. That results in the heating happening mostly at the top of the roller, and dissipating unevenly before it gets to the bottom where the film is applied. Overall, I was extremely impressed with the functional simplicity, the only real letdown was the lack of crowned rollers (which keeps pressure between the two rollers more even across the width).
The D&K Exp 44 Twin looks interesting, too, but I haven't seen it function yet. The big selling point (besides being low melt), is having a second path for mounting. In other words, you can mount without re-webbing your film, or you can set it up to coat your material in the top path and then mount in the bottom.
We just bought some D&K film from Pro-Image by the way, I'll let you know how it goes once our GBC runs out.