Shawn I'm in the same boat with my SA200's. I love them and will probably never part with them but they do not work for what I do most of the time. I had a trackhoe bucket to do this weekend, ran out of hardface wire so I thought hey lets burn the cobwebs outa the old 64 with some Stoody rod... Well I was almost done with the job when the armature shaft let go... Oh well she needed a facelift anyway so I'm like you and she's going to get a complete make over 100%, that’s the only way I like to do things.
About 80% of my welding machines are Miller and they have served me very well. I just sold my dads Bobcat that he bought in the mid 80's for AC power a couple years ago that had almost 5500 hours on it. It was a good machine and never had any major problems. We own a trucking company, fuel/oil transportation. I do repair work of every kind on our trucks and trailers on my days off because I have a full time job in Mining. I do mainly aluminum work so Miller was and still is, in my opinion, the best TIG and MIG machine on the market. I just bought a Big Blue 500D from (welderbrent) on here for the Aux power, CC/CV output etc... I needed a machine with three phase power so I can run my plasma at full rated output in the field and all I can say is it's nice to have 15KVA single phase and 20KVA three phase 240 power available. It is a HUGE machine, it welds great and will hook up to all my current equipment no problem so I am happy!
OK, I was looking at the PipePro and Pro300 also before I bought the 500D. I rented both of them to check them out and I can say I would never own a PipePro. Superior weld output in all processes because it is just a glorified XMT304 but it is too loud, pricy and prone to problems in my opinion. The Pro300 is a great machine. SIPS fuel, priced competively and welds great. I already have an XMT304 that I can plug into a Pro300 anyway so the PipePro was just not in the picture for me. My Rep can get me a brand new Pro300 and XMT304 for the price of the PipePro so let me know if you need any help there? This was a more versatile setup for me because I need something I can use in the shop or on the truck, space and weight are a huge concern for me! I know the Big Blue 500D is big and heavy but the price was right and well sometimes plans change... There is nothing wrong with Miller and they offer better service, ask Kaye Sellon what is a more reliable machine and I will bet she will say Blue! Our BigBlue Airpak's will dominate the Air Vantage machine in every way at the Mine and not one of them has been in for warrantee or breakdown, cant say that for the Air Vantage machines... Just my .02
I have never owned a Vantage 300, 400 or 500 but they are great machines and have great features. Most of the Rig Welders that built the mine I'm at had 300's and loved them. I would have no problem owning one if all my other equipment was not Miller, I'd have to replace a bunch of stuff! Lincoln and Miller 14 pin is different in every way so it's not an option for me. I guess it all depends on where you are at and where you want to go? Red or Blue is just a preference.
I put a 3000W inverter in my 74 SA200, run it off two batteries though so that is another cheap option. I also found a 4K Onan out of a motorhome on craigslist for a little bit of nothing... You can always get a CV module for the shorthood? All this adds up and depending on what or where you want to go in the now or in the future???
I'm proud of my Lincoln and Miller equipment and feel they are the best for what they do, it's a hard decision?
Wade