What software would be recommend?

[JAZZCNC]

I also see Mach3 and 4 are very common yet unreliable (I'm not totally sure why it isn't reliable but can someone explain or direct me to where I can find out)
I've also got solid recommendations about UCCNC using the UC400ETH controller

So what would you guys recommend that makes one software special, or why would you guys not recommend another software.

Mach3 isn't unreliable, Yes it's got the odd issue for certain users but so have others. The biggest down side to Mach3 is that it's no longer supported by Artsoft. They now only support Mach4 which IMO still isn't stable enough to be on sale with not enough support for Hardware suppliers.

Also don't get too hung up on the control software because for the average user with simpler needs just about all of them are more than capable and good enough to run 95% of machines. Mostly it comes down to personal tastes and dislikes of the screen layouts.

By the way, up till now I was thinking of purchasing either the Ethernet smooth stepper with Mach 3/4, or the UC400 with UCCNC.

Now Hardware is another story all together and it's here where you have to be careful and the software play's it's part.!
Nearly every External motion controller uses some form of Plug-in or Firmware type software for it to function. The Hardware supplier is usually the one who provides this, if it's using 3rd party control software ie: Smooth stepper/mach3 then it's very very important the Hardware people work closely with the software people when ever there is change. It's here where most fall down.!
The Plug-in is the heart of the controller and if it's not supported very well then at some point down the line, esp as the software updates, your going to get trouble.
Warp9 who make the Smoothstepper are just about the worst company at releasing updates or fixing any errors in there Plug-in software.

UCCNC software is made by the same Hardware supplier so they have total control when it comes to updates and bug fixing.
This is why UCCNC is starting to improve so much compared to Mach3/4. IMO the UCCNC as been much better than mach3 for quite some time but was let down by the fact it was USB, this isn't the case any more with the ETH versions.
Another issue for me personally being a builder of machines was the fact it didn't have any decent breakout boards that easily allowed 24v I/O and differential inputs. To me this is very important because of reliabilty. However this has also changed to some degree with Outside hardware supplier. Ideally I would prefer Both Motion control board and BOB to come from same hardware supplier but it's better than nothing.

SO my advise to new users looking for long term solution with relaibilty in mind would be this setup UCCNC with UC300 and UB1 BOB.

However I will clarify and say that, Mach3/4 or Linux CNC are more than capable of running any simple/medium machine straight out of the box using just simple BOB without any external Motion controller. OR UCCNC with cheap UC100.
IF on budget or just testing the waters with CNC then go with Linux CNC, yes will have bit of learning curve regards setup etc compared to Mach3 or UCCNC but still very do-able even for new user and there's plenty of help out there.

Hope this helps.