[Silicon-based]

The Dialarc/Idealarc welders have a much nicer arc than cheaper buzz-boxes, and they are industrial machines, built to last. Well worth a few extra $$ if the size and weight aren't a concern.

On the subject of power factor caps, I have to disagree with some of the above posters. You pay for watts, not amps. Unless you have industrial electrical service with a "demand" meter, the amps drawn at idle will not increase your electric bill. On the other hand, the lower current drawn under load by machines with power factor caps means that you can run the machine at high currents with a smaller breaker than with a machine without PFC caps.

If you look at the chart in post #9 by MinnesotaDave, you can see that at full power, the PFC version will work on a 50A breaker vs. a 70A breaker for the non-PFC version. This can make a big difference for people with limited power available.

John