I don't know what problems your talking about as i rarely ever hear anything but praise for the iPV's . I chatted with a few reps from P4U on a few different occasions and they say no changes have been made to the iPV 50 watt since it was released , the ones you could have bought months ago are the same you can buy today . At least thats the info i received
Now i'm not talking about the ones with the upgradeable 330 series S chip and the new design on the higher watt models , just the original 330 series non upgradeable chip versions. Despite what some claim a new batch or round 2 or 3 etc... does not always mean improved .
On the Cana mods they had a lot of issues when first released and continued to have issues so Cloupor and others had to try and rectify those and thats why you see improvements with later versions. With the iPV's , they were far more ready for prime time and they were being built by a manufacturer with a proven track record .
Cloupor was brand new to the game and only had experience with the Cloutank so of course more problems were going to be evident.
Side note: There will always be exceptions to the rule and some might have received duds or faulty units but the percentages of those is pretty low .