The Joying Android head unit arrived and has been successfully installed. Here is the current result:
First let me apologize for the crappy phone pic.
Second, I want to point out that my only disappointment is the gaps on both sides. In all fairness though, this was my fault. I was so eager to get it that I did not follow the Joying recommended guidelines for purchasing and measure the width of the space up front. I contacted their customer support and they do sell the face plate that should correct that issue for $9.99 US so I pulled the trigger on that last night. When it gets here (12-28 days free shipping :cry2

I will update the picture so you can see the fitment.
Now for the review. Quick version: I love it!
Detailed version: I have an older version in my MR2.
Now I am an audio enthusiast. In the MR2 I have completely removed all the stock audio and installed 10 speakers (4 component sets and 2 subs), have a 4 channel amp for the components and a mono for the subs. Swapping head units used to be a regular event for me. In the MR2 I think the Joying is the 4th head unit I placed in there before I thought I was done. Now I think I will end up replacing that with one similar to the new head unit I put in the 4Runner. Why? Simply put, the new HU does everything the old one does but faster.
In the MR2 the HU runs a rockchip processor with 1GB RAM and takes about 20 seconds to boot up. If I run the native navigation software and the audio for over an hour simultaneously the HU freezes up and I have to reboot it. I highly suspect it is lack of memory that is the problem but it is a situation I can easily live with because I honestly don't need the navigation software to get where I want to go when I have google maps on my phone for finding my way to an address in town. That and I use a different navigation app now that doesn't cause the same problems. That's the beauty of an Android HU. If you don't like the native apps just install the ones you do like.
For those concerned with quality of music I can honestly say now that both the old and new HU's will not disappoint. While the native app works fine it is limited in its feature set so I installed PowerAmp and without any tweaking was jamming out to my play lists off my mp3 thumb drive in seconds. The built in amp on the HU blew my Pioneer HU I just replaced away. I have new front component speakers coming today to complete the speaker upgrades (already did the rears) and will report on the final results some time soon once I have everything set. FYI, I have the completely stock SR5 (non JBL, non Nav) stereo system so I will be running no amps other than the HU (at least for now). No hissing, no crackling, no popping. Just clear music limited only by the stock paper speakers the 4Runner comes with.
Focusing on the 4Runner install, the HU is fully booted and on the second you turn on the ignition. That alone makes me want to buy another one for the MR2. It comes with all the same features (nav, 2 USB connectors, reverse camera capable, WiFi, 4G, etc - click on the link in the above post to see all the details) but it also comes with an Intel Atom Quad core processor, 2GB DDR3 ram, 32 GB internal SD, 2 SD slots capable of supporting up to 128GB SD cards, and buttons/volume knob. I know the last feature you might chuckle at but the one thing I don't like about my choice of the old MR2 HU is constantly trying to turn up the volume using the touch screen because you have to hit it just right. That and every time you turn it on the volume defaults to a lower setting. Now I just reach over, turn the knob and the volume stays the same every time I turn the ignition. Yes, it's a small pet peeve but if you ask me I would highly recommend buying a HU with the volume knob. All in all it is faster than any touch screen HU I have ever owned (including the name brands like Kenwood and Pioneer). It's running Android Lollipop 5.1.1 (versus the Kit Kat 4.4.4 I have in my old unit). It sounds just as good as the name brands and is far more versatile. Being able to spend less than $300 for a HU that allows me to create custom play lists, use my phone as a WiFi hot spot, and blue tooth audio and hands free phone calls. Did I mention the microphone that comes stock with the HU has out performed every non Joying HU I have ever tried to use for phone calls? No joke. On every Pioneer I have used I have to hang the mic on my collar in order to carry on a hands free conversation. WTF is that all about? Now I have the mic attached to the base of the turn signal stalk and can carry on a conversation without fumbling around trying to hook a mic to my shirt because the name brand companies decided to go cheap on the extras.
Finally, and most important when buying an Android HU, the customer support, forums, and even their own dedicated YouTube channel really sets Joying apart from the other companies that sell these head units. Honestly, you can get the same HU from a different company. I think they are all resellers of the same product so it is important that you do the research to determine which company is actually actively developing and supporting their product. Joying waited on releasing the Lollipop versions for a year just to make sure they were stable and fully functioning. Any time I have sent them an email I get a response within 12 hours (different time zones and all) and they will release new kernel versions with clear instructions on how to install the updates if you are having an issue. That and they come with a 2 year warranty on all their HU's makes them the reason I started buying from them. To date, I have not been disappointed with their performance. I have seen newer HU's running Android 6.0 on the market and was tempted to get the latest and greatest on the market but the vendor I was looking at weren't addressing glitches in the OS from the XDA forum I was researching on. All the best hardware in the world isn't worth a penny if the experienceis plagued with software issues. When I'm on a road trip I don't want to be getting frustrated by my stereo I paid $400 for because the developers were half assing it. I can get that experience from Pioneer and Kenwood any time. Lol.
YMMV, and you audio needs are different from mine but at the end of the day I got the head unit I honestly feel will suit my needs for several years to come for my 4Runner. A computer that plays my music, allows me affordable and reliable navigation, hand free calling, back up camera support, and tons more features that I can take advantage of should the desire arise for far less than any name brand is currently offering all in a plug and play package makes me a very satisfied customer (and no I am not affiliated in any way with CarJoying.com. I was offered no discounts or other incentives to write this review).