Costing only about $100, the Teclast P78HD tablet is a decent bargain 7" tablet. It has a quad-core Allwinner A31 CPU, a 1920 x 1200 display, Android 4.4.2 KitKat, microSD slot, and micro-HDMI.
It lacks GPS and not pre-rooted. I purchased from TinyDeal.com and added a couple of bucks for faster, more reliable ePacket delivery.
The original firmware v1.1.2 comes with a boatload of (unwanted) pre-installed Chinese apps, most cannot be uninstalled, using up valuable internal storage space and reducing available RAM. The Teclast tUI launcher seems to try to prevent the user from accessing all apps since it lacks an "all apps" circle button. It does have Google Play Store installed along with a Chinese TaiDian apps store. I immediately downloaded the Nova launcher to replace the tUI launcher.
General operation seemed quite snappy and the Retina display resolution was clearly noticed while playing movies. I did get the impression that internet web access seemed a bit slower than it should be.
The P78HD is much lighter (half of the weight?) of my Nexus 7 (2012) tablet. Most of the lower weight is likely to be from a thinner battery. So, the downside is shorter battery time and upside is faster full charging.
The light weight makes the P78HD more comfortable for extended use than the Nexus 7. That comfort, however, was diminished by the hard metallic bezel edges of the P78HD when compared to the Nexus 7's softer rounded edges. When holding the P78HD in landscape mode, the wider top/bottom bezel was comfortable. In portrait mode, however, it was much less so. For comfort, I would definitely recommend adding a soft case/shell, example: http://gd1.alicdn.com/imgextra/i1/67...-678991471.jpg
I unsuccessfully tried several links and ways to "root" the P78HD in order to uninstall all the unwanted Chinese apps. There is a Teclast app called Update. One of the advertised features of Teclast is its easier OTA updates. Since a new firmware version v2.03 was just released, I tried to update, hoping that the new firmware would be "pre-rooted". Using the "automated" option of the Teclast Update app, I got an error (in bad English) that basically said that the file could not be found.
I then searched for a link to download new firmware in order to use the Teclast Update "manual update" option. The downloaded v2.03 firmware ( http://dl.dbank.com/c0ckts308s ) comes packaged in RAR format. I used Windows 7Zip to unpack the *.rar file and extracted the actual *.img file. I also repacked the package as a new *.zip file. I copied the *.rar, *.zip, and *.img files to the P78HD's internal sdcard root directory. Unfortunately, even the "manual update" option just gave a failure message when trying to update using the *.rar, *.zip, or *.img file as source. My experience suggests that the Teclast "Update" app is simply broken, at least for firmware updates.
Next method, try the Allwinner PhoenixSuit Windows software included in the downloaded RAR package. The MSI install program is in the Chinese language but you can probably guess how it works. If not, here is a (not tested) English version: http://itead.me/ITEADDownload/softwa...nixSuit_EN.msi
I started the PhoenixSuit software. It asks to upgrade to the latest version. I connected the P78HD via USB and got this display:
I clicked the Firmware tab and entered my source file P78HD(C4A5).img location. It failed. As my programmer hunch, I renamed the file to remove the parentheses and put it in C:\ root directory. This time it starts working.
You have two options: (Y) format or (N) normal upgrade. I wanted a clean start without any leftover bloatware apps so I chose YES.
The v2.03 firmware transfer process starts and when done the P78HD reboots. Everything worked fine.
Upon reboot I note that there are far fewer bloatware Chinese apps. Of course, I have to go into Settings, find the "A" icon and change the language from Chinese to English (top line). Next, set up my WI-FI and add my Google Account. Then add a few apps, starting with Nova launcher. Unfortunately, v2.03 firmware is still not rooted. However, I decided to try Kingo Android ROOT again (it did not work with v1.1.2 firmware.) With the P78HD connected via USB, this time it seems to work but too quickly. I checked using a Root Verifier app on the P78HD. It says no. I then try the Kingo ROOT AGAIN option. This time it really works.
Now as a rooted device, I used the Root App Delete app to uninstall pre-installed Chinese software, users apps and a few "system apps". (For safety, you can use PhoenixSuit's APK tab to backup most of your apps first.)
Next, I ran AnTuTu and AnTuTu X benchmark apps to compare to my Nexus 7 (2012) tablet.
AnTuTu AnTuTu X Nexus 7 (2012) 13,309 13,730 Teclast P78HD 20,795 12,790
As someone who experiments with lots of apps, I have about 300 apps installed on my old Nexus 7. So far, I have less than 100 on the P78HD. One reason is that even by moving from internal to SDcard storage, you have to manage the internal storage space much more deliberately on the P78HD. Despite having 3 times as many apps on my Nexus 7, I am able to keep my internal storage usage considerably lower than on the P78HD. Regarding RAM usage, the Nexus 7 is typically under 50% in use while the P78HD is over 70%.
Bottom line: Google's optimizations on its Nexus line can make up for a lot when compared to better spec'd but less optimized competing tablets. For the price, however, the Teclast P78HD is no slouch in performance or stability. It is still quite a bargain if screen resolution, and micro-SD and HDMI features and cost are high on your list of priorities.