I am no expert on Pulse Arc, but I do have roughly 20 years experience using Laser Star laser welders.
A couple years ago I visited the weekend long Bench Jewelry Conference that Stuller held, and I did one seminar on the Puk Welder. I then sat down and played with the Pulse Arc machines that they had available, and I was pretty impressed at what the machines were capable of.
After several test runs, and admittedly, with the sales folks for the Puk looking over my shoulder I rechanneled an opal inlay, Sterling Silver ring, with good results, and no damage to the opal.
While I am not about to run out now and purchase a Pulse Arc machine, I do think that I could learn to do nearly every kind of weld that I now can do on the laser, with Pulse Arc, BARRING (and for me this is an important distinction!) welding deep inside crevices, holes and under galleries, which the laser excels at.
The arc will always take the shortest path, so welding in deep recesses will not be possible with the Arc.
Were I just starting out, I now think that I would opt for the Pulse Arc, and just send some of the more difficult and specialized work to a Laser Welding Jeweler.
One technique that I use daily on the laser is tack welding parts in place, and then going to the more traditional torch to complete the joints. This eliminates the need for clamps and jigs, allows me to fine tune, adjust, pieces prior to soldering.
The Pulse Arc would be just as effective at this, I believe.