Definitely an inverter.
I had Bester 1801 and I was not happy. Heavy and bulky. It was not uncommon for welds to be ordinary, not welded. The quality of the weld depends very much on the length of the power extension cord and the thickness of the wires used in it.
I sold and bought the Chinese IDEAL TECNOMIG 225 PRO CuSi inverter welder
Light welder, with the option of disconnecting and replacing welding cables. With braze welding function, which is very useful for car body repairs, and a socket for heating the pressure reducer. Bester did not have such opportunities.
In addition, IDEAL welds with a maximum current of 200A at a 60% cycle and Bester 160A at a 10% cycle. This means that when welding with maximum current, you need to take longer breaks with Bester. Not once during work, Bester turned itself off and forced me to wait for it to cool down - the welding machine's thermal protection was activated. I would add that welding with Bester powered from a 230V socket and standard 16A protection was a torment, because this protection was often turned off when the arc struck and with reduced welding current.
In the case of IDEAL, it has not happened to me that the thermal protection turned off the welding machine and forced me to pause, and turning off the protection of the 16A installation and at the maximum welding current occur sporadically and only with very intense welding.
The bester's advantage is, however, that probably the welder is less susceptible to damage, because it is a transformer welder, and it can also be supplied with 400V.
IDEALA only 230V. But with the power socket with greater protection at your disposal, IDEALA can be powered with an adapter from the power socket to the 230V plug, of course, 230V, and then there are no problems at all, and then IDEAL powered with 230V, welds better than Bester with 400V.
As for failure:
I used both welding machines for about 5 years each.
I had no problems with one or the other welding machine.
To sum up - I definitely prefer IDEAL
PS
If you have the opportunity to invest approx. 5 thousand PLN I recommend welding machine
Kemppi MinarcMig Evo 200
A welder that even a monkey will make a perfect weld. It is equipment both for those who want to learn welding and for people who want very good welds without the need to obtain a PhD degree in welding.
Of course, you need to have basic knowledge of materials and binders, but the selection of welding parameters in these welders is not needed at all, because only the type and thickness of the material, the type of weld, and the welding machine sets the welding parameters automatically. Of course there is also a manual mode.
I had the opportunity to work with such equipment and the next welder I will buy will be this one. For now, I have IDEAL, who does great in household chores and more.