I have my dads 1940/50's "Birdsell" on my repair cart ( a 2 wheeled wagon with a 25Kw PTO alternator, welder and pancake air compressor) I put together some years back. The idea was that instead of trying to drag a dead machine/implement to the garage and moving a ton of stuff to try to get room to fix it, I'd just hitch up the cart to a tractor and fix it in the field. Since building it 8-10 years ago I haven't had anything break in the field that needs welding!!! Figures. But that ancient welder will run a nice bead for an AC machine and it never fails to get running with the fan turning if I plug it in. I also have my FIL's late 50's/early 60's Marquette with the "stick the spud in the hole" adjustments. Reliable old machine, but not the Lincoln Ideal Arc I want. I'd like AC/DC but the little I've used DC makes me think I can get along with AC pretty good.
I have 2 MIGs, a Cebora and a Miller. Both were acquired in a trade and both needed work. I haven't run the Miller yet IIRC, but with clean metal and good wire the Cebora makes me look pretty competent. I tried flux core but solid and gas makes a lot better looking weld. I'm still learning to weld with the MIG, it's quite a lot different than arc or oxy welding. After my time in the body shop back in the 80's I can pretty much braze air to water, but my oxy welding ain't so hot. I can actually forge weld better than I can do fine oxy welding, and I have the bolt handles to prove I'm not very good at oxy welding!
If you go to any of the "shop floor" type forums or welding forums there is usually quite a bit of chatter on the little 110v machines. From what I've read a lot of the successful guys with those have a fair amount of experience to start with. They have their place, but flux core seems to be a hit or miss proposition for a lot of people. You'll never get that "line of dimes on their side" MIG look with flux cored. OTOH, I saw a guy weld in frame repair sections on a Jeep and it came out pretty darn good for what it was.
HF, a lot of people HATE HF, but a lot of people have a crap load more cash on hand than some of us. I've bought a lot of stuff there and some of it is pretty darn good. Some of it, like their so called "tap and die sets" are little better than thread chasing tools for nuts and bolts made from cheddar cheese, but their hydraulic 3 jaw puller is a life saver. Don't discount them outright. There are some good values for those with a limited bank account at HF.