Hi Michael,
The dimension is a heavy duty beast... a bit of overkill from what your saying your needs are. It would be damn near indestructible though...
We have a miller 350p at work. I barely use pulse on steel... its not really needed if your playing with in position welds. Pulsed steel works best with out of position welds on stuff too thick for normal short circuit...The advantages of pulse on thin stuff is kinda lost when running it manual. You almost need a robot(or at least a turntable if doing round objects) to move it fast enough to gain any real benefit versus short circuit.
I have ran more than a few spools of steel and stainless flux core (.045 to 1/16) out of the 350 at work without any complaint. The only time it really protested was when I ran 1/16 solid low alloy(110psi vs 70psi tensile) wire through it and was spraying it at 27 something volts and 400ish WFS... It got rather upset after a few passes (22" long) and shut right down without a help code and would not turn on for the rest of the day. It kicked on the next morning thankfully...
On top of it all you need to run a different gas for pulse. Pure argon for Al(50/50He/Ar if running Real thick plate...), but on steel you need something with at least 80% argon(the 5% makes a bit of a difference...). Fancy helium blends are Not necessary. 80/20 Ar/Co2 would work and be fairly close to the 75/25 Ar/Co2 short circuit people are used to on steel if you turned off the pulse.
Kinda the same sentiment on aluminium... I can spray wire up down overhead and sideways without a hiccup all day long on 3/16" and up... and its a lot quieter than the buzz of the pulse. I use both the XR push pull and a 30A spool gun, sometimes switching between the 2 on the same part depending on circumstances...
I kinda prefer the spoolgun... it weighs less than the XR and its giant freaking cable...
A bunch of what I said goes out the window if your using metalcore wires or are running enough production to warrant spending some serious time effort and testing to dial in your process... I live in a job shop where I have to bounce from various materials on a daily basis some times... very little time for playing and dialing in odd processes.
Regardless, the 350p is a solid machine and it will fit your described needs well(Don't get the Al Specific version!). All of that being said I personally prefer the Red 350mp... but that's me
-Clif The welder