Have you talked with Sportsmobile to see if they have had similar problems with this unit? Seems to me that if Sportsmobile sells this for use with their vans, it should work decently. Then again, after using a Powertank, anything else is going to fell like going back to an 8086 PC. SSSLLLOOOWWW!!!
I say if it doesn't perform to your liking at the next trial run, dump it on eBay or Craigslist and buy an ExtremeAire. Or get the unit on the trailer that ntsqd posted.:xxrotflma