From where I sit, the greatest complaint about either version of the 920 is that it won't do all that some want it to do. For those that had the original 920 and had it converted it will no longer do all that it used to do. The original 920 owners that suffered the conversion certainly have total justification for those complaints. I would be irate if I had a 920 converted and found out all that it had lost. Later 920 Plus buyers really don't as the truth of what the conversion did to the system became evident as systems trickled back to the original owners. later Plus buyers performing their "due diligence" had plenty of opportunity to educate themselves and make informed decisions. It's why I made it a point to publish all of my experiences with the 920 Plus thus far, good and bad, and conceal nothing. There was a need for further expansion as those making references in all the other forums either skipped over a few things, deliberately left them out, or made their observations so long ago that it was difficult to ferret them out. But they could be found with a little effort.
Thus far my only "complaints" are firmware and documentation related, with a battery issue on the side. The battery issue has been resolved at least well enough I no longer have any concerns with it. Others might still be chasing a multi flight hour rainbow but they'll eventually figure out there is only so much that can be had. Once they figure out that only so much battery weight can be added before the system consumes more energy lifting the added weight of the increased energy supply or exceeds the system's maximum safe lift capacity they tend to become silent in flight time/battery threads. With the Plus firmware it boils down to not having a histogram, where that feature is shown in the system menu. With documentation we have to remember we're dealing with Yuneec, who has a long history of screwing the documentation pooch. However, the 920 has a lot more documentation better than anything before it. The 520's is only good because someone other than Yuneec developed it. Either version of the 920 makes a great platform for those that recognize what they can do and structure their activities around the system capabilities as they are today.
When people buy something they need to be more concerned with what that product will do for them now, not what they might wish and hope for it to do later. Those that buy something "non industrial", thinking they were going to later get something for nothing, where a long history of continuous product upgrades had not already been established, or lack written money back guarantees of future upgrades, are extremely naive'. It's unfortunate, but a lot of consumers are extremely superficial and will believe or want to believe almost anything, later to find out their original perceptions were way off base. The first thing they'll do is blame the maker of the product. There may be a reason to believe they were misled, and there may not be such a reason. Companies selling to a mass consumer market often bank on misinterpretation when such perception is properly manipulated. Advertising is all about manipulation. We can see how that works in posts where people complain about not achieving manufacturer estimated flight times. More often than not the manufacturer did not lie to them and used flight time estimates with the words "up to" included in the time descriptions. It's not their fault some buyers don't read every word in a sentence, or lack the life or product experience necessary to recognize that advertising is always designed to present every possible positive related to a product while avoiding any potential negatives.
My family younger ones associate me with the term... Older than Dirt... and I'm certain yer on the + side of me. 
Hopefully my debating, challenging, sharing or elder raw humor has textually passed in a receptive tone. 
