I have had a good experience with my Everlast MOSFET machine (a "super200P"). I have a feeling the "poor track record" you mention may not actually be a true representation of the product, and may just be relating to random internet posts, which are likely not truly representative of the machine. It is a fact that at least as far as the earlier MOSFET machines were concerned, that everlast and longevity had their machines made in the same factory, I believe.
If I could do it over again, I'd try and get variable AC frequency, if I could swing it at all in my budget (this is a feature on their newer IGBT machines...) as I love doing aluminum and focusing the arc is helpful. I'd so glad I got the pulsing feature as well, as I've tried it lately and find it is really useful, so I'd recommend that feature to be on the list as well. Definitely get the foot pedal, but consider skipping on the Everlast/longevity argon regulator if it saves you money - they just suck too badly (and read in funny units.) I had problems with two of them leaking out expensive argon gas. You can get a good one from HTP or comparable model on ebay, all brass, reading out in proper CFM units, reliable, and with proper CGA-580 connection, elsewhere for about $40 shipped.
I find myself not using the sequencer/torch switch very much, but, it may come in handy on some projects.
I'd get as much power as I could swing, as I find myself using the full 200 amps my machine offers, and it might be desirable to have up to about 250 amps if I could swing it. It is nice to be able to run off a smaller (I am running fine off just a 30 amp breaker!) power supply circuit, though.
I'd skip the combined plasma cutter feature, and just get a separate box for that, because I find switching from TIG to plasma and back is quite inconvenient and I don't really like having the quick disconnects in the argon line (potential source of argon leaks or contamination.) A water cooled 9 series torch would be a nice upgrade.
I believe the earlier longevity and everlast MOSFET machines were made in the same factory, although the newer machines seem to no longer have identical features, so apparently they have become different now. I can vouch however that everlast takes care of their customers very well, if you experience a problem, they are very responsive to helping customers that call them.
Now granted, if the prospect of tinkering under the cover of the machine scares you, the low cost Chinese welders may not be for you. I prefer fixing the machine myself if I can, instead of returning it, it allows me more quality control, and I can usually learn something new about the machine or electronics in the process. If you plan on the machine needing a little TLC when it arrives, you will not be disappointed. For example, I would plan on taking the cover off, and visually inspecting things at least. Make sure all connectors are fully seated, nothing is flopping around loose, everything looks good, etc. Maybe double check the high frequency gap while you are at it. I performed just a little preventative maintenance on mine up front, and have not had it break down yet. I had some (easily fixed) issues with broken hose clamps on the argon hose connections, for example. I'm on my fifth argon bottle now, and I find it TIGs nicely and reliably! Plasma cutting works too, it's just a bit of a pain to switch.
I,m a retired Tool & Die maker. I kept some of my equipment for retirement & having fun justmaking stuff. I,m no welder like some of you, but I can weld fairly good. Nothing like Jody forsure. But I have been welding Tig, Mig & stick for many years off & on. Remember I,m a machinistnot a welder.But I have searched the net on cheap China machines. I guess the price is why. But what inspired thispost is some guy on the net said this. He said a lot of the burn down on these machines was the routingof wires in hot places, transformers & such. I,m no sparky by any terms, OK. But can any of you guys that knowelectronics think these machines can be upgraded to give them more life?Funny how Americans can up grade ANYTHING. I love Blue & Red believe on that. My mig & Tig are both MILLER.I would NEVER sell ether of them unless I had to. But these new ones have gone past the old Transformer onesI have. I really would like to be able to adjust frequency as you can not with the old transformers.That is my only thing about the ole guy machines. But if you are not a good welder you can over come that.I,m not that good. But it would be cool for us limited income guys for some way to make the china craplast a little longer, than the report I keep hearing.GOD I love this form & Jody for helping us with his knowledge. the net is so GREAT with forms as this.Thank each & every one of you for helping this Ole fellow in my retirement. God bless you all.Fly