That looks like an OK machine, but since it is a knee mill, I personally would go for a used bridgeport or other quality brand machine. A decent one coul be had for about 1/2 the price of that Grizzly mill.
Some of the pros and cons I see with that mill compared to a bridgeport are:
Pro - VFD controlled motor
Con - Smaller table than a bridgeport
Con - Ram does not extend like a bridgeport does
Con - It doesn't appear that the head tilt has a worm drive to assist in tilting/raising the head and tramming.
You expressed an interest in CNC, and having worked as a machinist on manual and CNC mills, I have the following observations. A knee mill can definitely be made into a CNC machine and I have worked on several that were. One that I worked with was X and Y axis only with manual positioning of the Z. Several were X,Y, Z with the Z axis being movement of the quill. One that I worked on had a goofy setup with X,Y,Z1,Z2 where Z1 was quill, and Z2 was the knee.
The X-Y only would be easy to do, but it is a bit of a pain to work with just X-Y.
The XYZ with quill feed works very well, but you are limited in Z travel a bit. On those machines I found myself haveing to raise and lower the knee sometimes to change tools, or get clearance, or similar. Worked pretty well though and since raising the knee is accurate and you don't lose XY position it wasn't that bad.
The machine that had X-Y-Z1-Z2 worked reallly well, but we never used Z1. All the guys that used that machine quickly found out that it was much easier to just program all of the Z moves into moving the knee. It worked really well.
The thing you have to consider strongly on converting a knee mill is what system you will need (servo or stepper), and what that means to cost and setting it up. They can be converted and make very nice capable CNC machines. Depends on what you want out of it.
Having said that, consider that a true VMC does not have a knee. They work by having a bunch of head travel. This is exactly how a square column mill drill works. Sure they have a quill too, but when CNC'd the quill is generally not used, so esentially you are mimicking the way a VMC works. They also work pretty darn well for a manual mill to if that is how you want to start out. The square column mill drills come in a variety of sizes from table top model that one guy can carry easily up to almost 1000 pound monsters. All of the mill in this range have been converted to CNC at one time or another.
If I were going to buy a mill right now for my own personal use, with the experiences I have had, I would buy a square column mill drill. Depending on what you want to do with it would determine the size you would go for.
It sounds like you may not have much machining experience, so might I suggest that you try the lower end of the scale instead of sinking $10K into something you may not need. You can get a mini square column mill like this one:
G8689 Mini Milling Machine
Then CNC it and have a whole lot less money into it than buying something that may be great but overkill for what you actually want to do. These can be made into pretty good little CNC hobby mills as has been shown many times by many people. Are they suited to mass production of large parts? no, but they can get you a lot of experience with machining and CNC.
Just like you don't need a sledgehammer to drive a finish nail, you don't need a CNC mill with a huge table if you want to make small parts.
My opinion (Worth what you paid for it)