It seems his tablet couldn’t get the update that fixed YouTube audio sync issues. And in the video, another audio issue pops up live when he tries to play Temple Run 2.
Some spec screens (click = big):
He didn’t have many apps on it …
… and none look particularly piggish. Yet he still encountered issues with the OS stuttering.
Overall, the performance was unacceptable to him and he returned it.
In a Comment, I let him know about all my posts and the OMA ROM and rooting. But the tablet was already back at Best Buy (where another hapless customer will probably get it sold as new, despite being used!).
His video:
In a Comment at my prior blog, reader TimoBell pointed me to an iFive Air ROM of Android 6.0 that incorporates MultiWindowing: RK3288: IFive Air Marshmallow Edition and Downloading AOSP ROM CrewRKTablets RK32 Air MM 6.0.1 build v1.1a – please be patient. I’m skeptical that ROM will work on the Flex. There could be some hardware differences that could brick it. But if someone out there is adventurous enough to try, please leave a Comment — and, if possible, post a YouTube video showing the MultiWindow Android at work. Next-day update: I would not try to install the iFive Air ROM on the Flex. I took a trip over to the iFive Mini 4 forum [Google Translate] and there’s still no release of Android 6.0 for it. If it was simply a matter of installing the Air ROM on the Mini 4, the Chinese would have done this months ago and the forum would have been filled with happy users instead of the miserable and abandoned users of today. There’s probably hardware differences that would cause the Air ROM to brick the Mini 4 — and the Flex too. I’d rather be cautious about this than encourage people to ruin even a cheap tablet like the Flex.
Over at the ARCTablet forum, bobb reports about his battery transplant:
Managed to put a 6000mah battery into the tablet (3.5 x 66 x 125) added about 8 grams to the weight. Was a pain!!
Running it down now, so i can charge from empty and see how long it lasts.
And:
Temperature is good, gets a bit warm, but not much. I use a 2.5A charger and it doesn’t heat up while charging (charge takes approx. 1 1/2 hrs).
Overall, usability is much longer. I don’t play games, but for streaming video and browsing lasts much longer.
Best Buy again had this tablet on sale for US$99. I’m not sure if it’s worth more than that, but even US$129 might tempt me if the sale intersects with spare money in my pocket. But really, I think it’s worth only US$99 and wish Best Buy would drop the price to that permanently.
As Mobile World Congress approaches with new tablets due to be unveiled by both Asus and Samsung, Best Buy’s window of opportunity to sell this tablet is closing.
Previously here:
Video: Insignia Flex Elite 7.85 Unboxed As Broken
Insignia Flex Elite 7.85 Innards Described
Mike Cane's Atomic Supermen 
I got it for $89 (clearance, late June 2016).
I’ve installed the latest 1.0.10 firmware, enabled Developer Options, enabled the experimental media player, NuPlayer, in Developer Options. Rebooted. The sync problem seems under control.
There is still ocassional studdering, but its lasts less than 2 seconds and mostly at the beginning of an app starting.
I also installed Dimly (to go below the system min. brightness) and Rotate Control (an app to control rotatation).
For less than $100, its pretty good.
Unfortunately, I doubt Insignia will continue providing updates. I only bought this until I have enough money to get a Xioami Mi Pad 1. Xioami has been reliable in coming out with regular firmware updates.
Thanks for letting us know.