I've just started using UCCNC with the UC300 controller I used to use in Mach3 via a plugin. Initial impressions are very good. It is a lot more simplistic than Mach3 but on the flip side if you're a hobbyist like me you can actually understand all of what the software is doing rather than being presented with a myriad of settings which are about as much use as if they were written in a foreign language. Plugin support is very limited at the moment but hopefully this will grow given time and I hope to teach myself to write my own. I find jogging on it much easier than Mach3 and its responses to keyboard inputs for jogging are much better. I found in the past that Mach3 could miss keystrokes and your zero position would move with obvious bad results. Mach3 is good but time and technology move on to the future and I think UCCNC for 45 Euro is a very good alternative to moving to Mach4 Hobby for $200. The only restriction is that it is designed to work with the UC100 or UC300 interfaces but these are a great option in themselves if you struggle to find a PC with a parallel port now.