Grizzly (at least they used to,) does have repair parts and I have heard good things about their service. I don't know about Jet but with Enco, once they have your money the warranty is pretty well over.
For a hobby machinist or light job shop type work you are probably okay with any of them.
One thing, I would advise for you to make sure the mill has a motor that was made in the US.
Good luck, Joe.
I used to pine for a Smithy, especially the one with a 36" length between centers. It's a combination mill/drill/lathe, with a 4-jaw chuck and other goodies.
But, no matter how good it is, I won't buy one.
Why?
MADE IN CHINA. (damndamndamndamn)
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Happiness is a 200 yard bughole.
The basic comment on imports is they aren't the same quality as the machines they try to copy, but you can still do denct work on them. A bridgeport style mill has enough mass to make it rigid enough to do good work. The key is to spend the time dialing it in when you get it, and you should be happy.
Enco used to have great prices, but it seems that Grizzly is now the price leader. I plan on getting a grizzly 12X36 lathe in the future, though would like a 13X40.
As far as the 3 in 1 tools like the smitty, they are a complete waste of money, not rigid enough to do good work. One would be much better off with a good lathe and drill press then a 3 in 1.
Let us know what you come up with and how it turns out!
I would highly recomend against used equipment, most often it is very exspensive scrap metal. The import machines have their flaws, and are works in progress, but are in servicable shape. On the other hand, most used machines are so worn out that it is impossible to do quality work w/o a complete re-build, and unless one has a complete shop and the skills, that can easily cost more then what you bought the machine for. Shipping can also be a killer, a friend had a lead on a free used bridgeport, but the shipping would have been $1500, and that was too much for a machine bought sight unseen.
A used American manchine in decent shape will be ~ twice as much, or more than an import, unless you happen into one of those once in a lifetime deals of the century. The used machines in decent shape are being bought up and converted to CNC. You used to be able to find a used Hardinge for $10k, now they are up to $20k as the CNC conversion market has increased their demand.
Lots of folks like to bash the imports, but most of them are serviceable tools. A few I would stay away from are the 9X20 lathes, they are too light and the gear train is junk. The 12X36 machines are borderline exceptable, and the 13X40's aren't bad at all.
The mill/drills are a mixed curse. They are quite a bit of machine for the $, and the rong fu's are decently built, but, you don't have precise control over the Z axis, but, you have to tripple your investment to get to a B-port type machine.