Just my 2cents.
I used to have a bobcat and a superS32p. With .035 wire I was never able to get stable high end wire feed. Miller rep finally told me that the Cat is not a "true" CV" welder. One look at the Volt/Amp curve compared to say, TB302 holds up this statement. 400 or so ipm @28 or so volts is getting into spray parameters that may or may not work w/75/25. That aside...I think the Bobcat welding volts drop enough at 250 amps that stable spray is not possible. I hook a DVM to ground and the gun clamp inside the feeder and check the actual arc voltage while welding (kids come in handy). I found with the 'cat' I couldn't ever get enough voltage for stable spray. I now have a TB302 and all the calculator numbers work as they should.