I perfer the miller 252 over any lincoln mig welder. I have used both and the miller welders smoother. Never really had problems with the miller. When you make your choice, I got one for sale.

When comparing similar machines (and I am not familiar with the L255) I sometimes find asking about the country of orgin makes the decision an easy one.

You may find one of those two is made in either Canada or Mexico.

I have ran 7 lincoln 255s and they are a tough machine to beat.  Now only two of them were the newer xt with the fine adjustments on the front and most guys in the shop including my self thought the older 255 models we had ran smoother. But that's not a good opinion cause once you get set on your machine a new machine seems to never weld as good as the last one you spent a few years on lol.  We ran mostly 35 wire and mostly downhill  we did have one station set up with 45 wire and at 27 500 it was constantly overheating the machince wasn't big enough for that application 8hrs a day.  None of them gave us any "real" problems just the normal wear and tear stuff, on off switches rollers etc.  Had a lot more problems with out 300 amp machine and remote wire feed

We also took the factory guns off when we got them and upgraded to a 300amp magnum,  had one with a spitfire on it?  This makes a huge difference imo!

The miller 252 I ran I didn't care for I think any of our lincoln 255 would walk all over it but it still had the dinky factory gun which gave me fits so my opinion might be a little baisis now the miller had the spool gun attachment on it and I was impressed with it considering the set up it did alright. I'm used to running a spool gun off a sa 200

I have a miiler 200 sync tig and it's a great machine but if I had it to do again I would buy the dynasty,  But I'm always pushing my tig machine harder than I should

Now that being said that's just my exsperience on our applications. Miller and Lincoln both make excellent machinces and for just starting out I doubt you can go wrong with either model

Keep the dust blown out of them and I doubt you could wear one out,  no one was harder on the 255 than us!!

Unless You don't like yellow, have a look at the Esab Migmaster 250 as well. A friend has one, He thought it was a good machine.