This is my review of the Teclast X98 air II (HG9M) Specifications On paper, the tablet is a beast, with a Z3736 Bay Trail processor, 64Gb of storage, 2Gb of ram and a 9,7 inch 2048x1536 ips display (the same one in the ipad air it seems).The tablet is dual boot, depending on which version you buy, you get either windows 8.1 or windows 10 with android Kikat 4.4. Build quality The tablet is, well, very similar looking to the ipad. It's made out of aluminum, it has the same size than the ipad air (the teclast is just 0,4mm thicker), it's a 4:3 screen ratio. The tablet is well built, it's not as good as an ipad but pretty close, the aluminum makes an impression of litte less quality than the ipad but overall compared to other android tablets out there it's pretty much one of the best build quality you'll get. I do hear some very tiny creacking near the speaker sometimes when I pickup the tablet but in other hand it's very solidly built. Buttons are made out of plastic but I haven't found it to be a problem. They feel great and look nice. Screen There is not much to say here, the screen is georgous, it's bright, it has an excellent resolution, the colors are great and viewing angles are just as good as the rest. It's hard to say what this display could do better, it's one of the best ips display you will find ont the market these days. Cameras and speakers Considering the price of the device, some corners had to be cut somewhere. Both cameras and speakers are it. Like most tablet the rear camera is bad, but this is worse. I haven't tested it for a very long time but from what I've seen you should not use this in any other case that you absoluty have to (matter of life or death). The front camera is not good either, if you are a heavy skype user or else, this is not the tablet for you. The speakers are not as bad as the cameras, the sound quality is good, not great, it lacks basses but voices are clear. But in the end I recommend using headphones or externals speakers if you are listening to music for a long time or watching a movie. But if you want to show someone a video or listen to a little bit of music it will be perfecty ok. Battery life I'm not really an expert at reviewing battery life plus I haven't used the tablet enough to do so. I'll just say that the battery life seemed good for the time I used the tablet. Also the battery is draining faster on Windows. Windows 10 Now this is where the crazy stuff start. Crazy good and crazy bad. First, if you read all this and you have never flashed a rom on an android device or did Windows install, this device is not for you. The tablet is shipped with either Windows 8.1 or Windows 10. I don't know what the "stock" Windows 10 install looks like because mine came with 8.1. To go from 8.1 to 10 you can just update it with the Windows 10 update tool provided by Microsoft. But from the moment the tool finished downloading Windows to the moment the install was done and the Windows setup started, I was stuck with chinese. Now I think if you go in the setting and put the proper region setting you should be fine, but it's not because your device is in english that the install will be too, I think you need to change the location settings. Once you install is done you'll just have to install the accelerometer drivers for windows 10 and all will be working perfectly. If you plan on using your tablet in an other language than english, note that when you will change from english to whatever your language is, you'll need to login with you Microsoft account in order for the apps (like mail, calendar, store) to change language and it takes a little while. Windows 10 work well. Everything is fairly smooth and responsive, despite windows 10 heavy animations. Only opening apps or goining back to home in tablet mode doesn't show a smooth animation. I'm not gonna review Windows 10 for both desktop and tablet but I think it's great, the soft keyboard is the best one you'll have ever seen on a tactile device. I promise you. I mean you can do copy, past, cut, and select all from you keyboard! And you have left and right key to move in your text. Also you now have an option to popup the soft keyboard in desktop mode. Edge works fine, also coming from android, the scrolling seems much slower. I tried Firefox and had terrible performances, same thing happened with Chrome. I wonder why that is, if the tablet is not fast enought to run a full web browser other than edge? Or if Microsoft did some optimisation on edge that other web browsers can't benefit from (that would be evil)? The lack of apps is still terrible, Facebook is not a great app, the Twitter universall app is ok but need some real bug fixes and of course there is no Youtube app. Last complain would be not being able to see battery percentage while the tablet is not in charge (after doing some research, apparently this is a bug related to windows 10, clicking on battery icon will not show the popup if the tablet is neither charging or in power saving mode, which it should). Android First it comes with android 4.4 so if you don't want to be stuck with it and go for lollipop you'll have to flash this yourself. It's not very complicated to do so, and you will find all tutorials you need if you know where to look (mostly techtablets.com and xda, maybe on MoDaCo soon). Now Android is were all my excitement went down. There are a couple of Roms out there, one have small changes to soft keys and is debloated another one is just stock, like teclast made it. I've flash 3 differents roms, now I have the teclast one (non debloated). First my sdcard is not working (it is working on Windows 10), I think it's because it's a 64gb but it should be working anyway. I didn't find a solution to this problem yet. But my biggest disapointement is performances. I was expecting to have something snappier than windows 10. Animations such as launching apps, scrolling in recents apps, launcher scrolling or scrolling heavy things like facebook are all laggy. Now when it is only ok in portrait mode, the landscape mode is a nightmare, everything lags. I don't know why that is because, the gpu seems to be working perfecty, I was able to play 1440p video on youtube perfectly and play games with no problem. So I came up with two possibilities, either the resolution is too much for the cpu gpu but in this case why is Windows 10 running pretty good while being much heavier? Or it cames from the fact that the rom is not correctly optimised. Maybe this is what it's supposed to be on such tablet but to be honest I was expecting high end performance in Android considering the Bay Trail processor. To me it is not high end it is perfectly usable but as a very exigent person in the snappiness area I was really disapointed. Conclusion The teclast X98 air II is a great piece of hardware which has very little flaws. If you are not planning on taking photos on this tablet you can't really go wrong here. On the software side, if you want to use Windows 10 a lot, for the price it's great. If you are planning like I was to use this device mostly on android, well for the price it's still great but if you expect high end performances in the android UI you will be disapointed. Edit: A simple formating of my micro Sdcard fixed my issue on android, so no problem here.