I think that solid material witnesses on the units you mentioned may be few and far between on this forum, not that they are non existent here, but just rare. These units are typically out of the practicality range for many of the guys here. It's not that they don't have the money, time or experience, to have one, but a farm equipment website lends itself to guys who either farm full time, or see it as a hobby. Both of which typically don't favor TIG as a welding process or don't want to budget that kind of money for something that isn't used full time. Guys like Shield Arc and a few others do have experience, but a lot of the experience is with older equipment. Obviously, I work for a competitor product as well as a couple of other guys lurking around. I'm not going to try to convince you to look at mine since you are pretty clear on the units you have in mind. I have looked at and operated the Miller and Lincoln Products. I am full aware of HTP and it's reputation and specs. The Miller Dynasty 200 would be a little under powered for the price range you quoted. Keep in mind it's barely a 200 amp machine, with a limited duty cycle on 220 single phase at full output. I haven't looked at the Lincoln specs lately on the 205, but do remember it having similar specs. If you can stretch your budget, I'd go to something with more amperage and better duty cycle. HTP has a good unit, on specs alone...but I have not welded with it.