I have had a Lincoln Weld Pak 100 for 15 years and it served me well and took much abuse and survived. I like it a lot but... it is 120 volt powered, convenient, but limited in amps and not good for 1/4 inch steel in a single pass.
I recently bought a Hobart Handler 210 which welds circles around the little Lincoln. It should as it is about as powerful a portable (no wheels and has handle on top of case) as I could find. It is a nice MIG and will deliver up to 210 amps which will do 3/8 steel. It will also do aluminum with the included accessory spool gun. It out performs my AC/DC Lincoln stick welder.
About the portability... It has no wheels, is not much bigger than the Lincoln and... It does have a handle on the top but... with a large roll of flux cored wire installed it tips the scales at about 88 lbs. I pick it up and carry it around but not very far for very long. I mounted it to my welding trailer but you can't always get the trailer up close to what you want to weld and (recall folks) the leads on a MIG are only about 10 ft long.
I redid the mounting arrangement so it is easy to remove the welder to roam around within my 60 ft extension cord range. (Extension cord is 240 volt 50 amp capable and only a little more portable than the Hobart) I will be making a cart with large diameter (off road/uneven terrain) wheels for the welder so I can get to work areas within my extension cord range of the trailer and its generator but where the trailer can't go.
I have never used shielding gas with a MIG before, always opting for flux cored wire but I am anxious to try my hand at aluminum welding so I will be buying a bottle for shielding gas, probably at least two (if not three), one for argon and one for C25 (75% argon and 25% Carbon dioxide.) From what I have read just carbon dioxide does not give as good of results, especially at lower power settings but it is cheaper.
Pat