HTP has far better support Than Miller. I have a Millermatic 250 and it's a solid welder. I will mostly be welding thin stainless, CM steel and occasional aluminum. If I get a Dynasty, I will not be able to get the same features as the HTP, a similar featured Miller is $1500 more. Maybe $2000 more. I do like the controls better on the Miller
I'd be tempted to give the HTP 221 a try if you are going to just be welding a few hours a day on the thinner stuff.
All that said, I have a Miller 280 Dynasty without cooler right now and it has way more features than I'll ever use on a daily basis. The price on the 280 has climbed substantially over the past years, to the tune of $1200 more since I purchased. You can get an HTP 221 with water cooler and the works for $3200. The HTP 221 should easily cover the thin materials you plan on welding.
