I'm owner of a Lenovo A1000-F tablet. The only negatives I've found are the lack of apps storage (I cannot update some apps) and the version of Android is 4.1.2 (I didn't search how to upgrade or change ROM).
The lack of storage can be solved if I install a program that links the apps to the SD card. Unfortunately, this program needs root access. I was searching how to do that and I finally did it. It's very easy. Here are the steps.
1. Go to your tablet and enable the following:
Menu>Settings>Developer Settings>Enable USB Debugging
2. Connect the USB to your device.
3. Download and install the PdaNet+ for Android
During installation, it'll find your Android device and it'll download and install drivers. After installation, there's going to be an icon at the task bar.
4. Download and install the KINGO Android Root tool.
5. Run KINGO and just wait until it'll show you that it was successful. It might take a lot of time. Just be patient.
6. Reboot your tablet.
To check if your tablet is rooted, you can download a program from google play.
Check out the video: