I think the main difference between ISPConfig and 42go is in terms of support. For 42go you can have professional support from projektfarm GmbH, whereas for ISPConfig you must use these forums
Hmm, If we aren't getting professional support here, I wonder what kind of support you give over at the paid script. You fly over to our workplace and fix it yourself?
Seriously, the support you and till give on this forum is nothing less than professional.