Take it from a guy that has and STILL IS trying to upgrade from 3-4. It will make you very angry and there is a huge learning curve and anyone suggesting there isn't is full of it. Mach4 is a good software for programmers and not DIYers. There are a lot of mods that need to be done not to mention the setup of the pins, spindle, etc. I work on mine a little and then walk away so I don't drop kick the computer. Here is a small example, my WORK ZERO does NOTHING so I have to go in and modify the script to tell it to work. You would think that would be a "from the factory" thing but evidently it isn't. Just several little things like that that can make you say WHY DID I JUST SPEND $200 ON THIS!! I am still hoping I can overcome, and it works good in the end but I am still using Mach3 after almost 8 months of switching over.
No disrespect meant here at all. I'm just trying to point somethings out that may not be obvious. There is a certain amount of setup that has to be done with Mach 3 or Mach 4. Buying an OEM machine that is preconfigured relieves you from becoming the "machine integrator". However, the OP has not used Mach 3 before so he doesn't have Mach 3 habits to break. Like it or not, that is what it is. We all get used to doing thing a certain way and resist change even if change will make something better. But make no mistake, if you built a machine and installed Mach 3 from scratch, you would spend about the same amount of time configuring Mach 3 as you would Mach 4. It is just different, not harder. Just different.
BTW, the "Goto Work Zero" button used to move X, Y, then Z. But people who had just 2 axis machines complained about trying to move the unconfigured Z axis. Then we made it just move X and Y without touching Z and people complained that they crashed their Z because it didn't move the Z to a safe level. So then we just made it where you have to make it do exactly what you want it to do. And people still complain.
When I install Mach 4, the only thing I will touch after setting up the motion controller is the "Goto Work Zero" button and the keyboard bindings if I'm not using a panel and the machine doesn't have a tool changer. It runs machines quite well "out of the box". Now, it may not be how you want it to be, especially if you are used to Mach 3. And then you are going to have to learn a bit to customize Mach 4 to your liking. I see a lot of Mach 3 users wanting to change Mach 4 to be more like Mach 3. It is like upgrading from XP to Windows 10. Sure XP was good, but so is Windows 10. But they are different and most of us don't go trying to change Windows 10 to look or act like Windows XP. And I think the reason is there just isn't much way of doing that. Maybe we shouldn't have made Mach 4 as configurable as it is. But that is what people told us they wanted when they couldn't "do" some task or functionality in Mach 3. So we have figured out (very painfully I might add) that we can't make everyone happy.
Also, I say this over and over. Mach 4 is not Mach 3. Just like XP isn't Windows 10. Which Mach is better? Well... one (Mach 3) hasn't any development on it in nearly a decade. In fact, it
REQUIRES an XP machine and a very old compiler to compile it. The other (Mach 4) is compiled daily and actively developed. I'd go with Mach 4 for that reason alone. How long will Mach 3 continue to run on modern versions of Windows? They (Microsoft) basically made it where the parallel port plugin won't work anymore already. And the very compiler that Mach 3 used (written by Microsoft!) will not run on anything newer than Windows XP. So that would be a very real concern for me. But that's my opinion. I'm rather like Craig and would start slashing if I had to go back to Mach 3.
And to the OP, I hate it that you got one of those Chinese controllers. I know the price was appealing vs. others but it is usually just wasted money in the end. I wish there was a way to put up a huge warning anytime someone searched on hobby CNC machines that says "Noooooooooo!". Those guys will probably bundle their machines with Mach 3 for 20 more years. Why? Because they can't bundle it with Mach 4! And I don't think they can bundle with LinuxCNC either.
Steve