I don't think its true for me. I have, and use daily, an ipv1. They didn't make it for long as it seems the masses wanted 50W or more. It is accurate and has never given me any problems.
I did buy an istick 50W. It was through a group buy and cost me about what I paid for the 20W one. Longer battery life, flat DC signal, better 510. I expect to be happy with it for those reasons. I'm giving the 20W to a friend because she's poor, but otherwise I would keep it.
I do have a number of dual and tri coil rtas now, and 50W devices are helpful. What I want most when I choose mods is accuracy of the chip and a good 510.