I've had good results from gasless MIG, simply using a cheapie MechPro unit from 'RepCo' (the big barn motoring accessories place down-under).
A bit of practice with an old washine machine panel and my mate (a qualified welder) holding my hand* , and even working outside on what was admittedly a fairly still day, I was pleasantly surprised by its ease of use and minimal splatter. Like any welding, get your settings right and go slow and you'll get there.
I've now invested in the optional gas pack but haven't tried it yet. Probably a game-changer but what we achieved simply with gasless was not too bad at all. And a flapper disc will clean things up anyway.
For big jobs, I'd still favour trad. oxy. welding (I've never tried TIG) but gas / gasless MIG has its place.
* Not literally holding my hand cos that would be a bit weird