Nevertheless, I'm a proud owner of such a slate, and I want to share with you some tips that could help you with the Slate 21. Some of those tips will require root privileges.
Please note: So far, it seems that HP is doing their best to block any rooting attempts. Their latest update includes security patches from Android 4.3 and 4.4 which prevents all known rooting methods from working (and I tried all of them so far). However, when it comes to a chase between HP and Android "hackers" - those "hackers" will win (there's not a single Android device that hasn't been rooted so far, other then this Slate). Remember - if you root it (or unlock it), your warranty is lost.
So here are my tips, some of them requires root, and when such a tip requires these privileges, it will be marked with root:
- Do you plan to do some serious typing and you're a fast typist? switch keyboards from the bundled one to a more professional one (Logitech and Microsoft got some serious keyboards). As a person who types 80+ WPM (Words Per Minute), I find the bundled keyboard useless for my needs.
- Want to use another keyboard and you're missing the Android shortcuts? you'll need a new app for that. You can try "external keyboard" (which is free), and if that doesn't suit you, try the External Keyboard Helper Pro (which costs around $3) - the latter will give you tons of options to configure any key to any Android action, it also let you select which keys to use to switch Layout and other nice features.
- root The Tegra 4 in the Slate 21 is clocked at 1.66 GHz, which is really slow (compare that to the Asus TF701 which is also a Tegra 4 based device and it's clocked at 1.9 GHz). There are some "mods" which envolve kernel modifications and recompile to achieve a serious speed boost (the nVidia Shield users/hackers at XDA reached 2.55 GHz!), but be careful with that! The nVidia shield got a fan, the Slate-21 doesn't, so you could easily fry your Tegra 4 (although you'll probably won't fry it, you'll get a very unstable machine).
- root 8GB Space is really, really a small place when you're installing games, downloading videos etc. Although it's not possible to completely move apps to any external storage to SD, you can move the apps+data with some apps that will do it for you. Check this video how it can be done (although this video is talking about Galaxy S4, it's the same app and same method with Slate 21). This will give you the space that you need so much. Before doing that, remember to get a Class 10 SD Card (and don't format it as exFAT or NTFS, the Slate's kernel doesn't support those file systems fully, only FAT32).
- USB ports are different! Don't ask me why, but it seems that the USB ports in the Slate 21 are working differently compared to other devices. Examples: if you plug a keyboard or a mouse to the USB port on the left, it won't recognize it, so if you're plugging any USB device and you don't see it being recognized, try to connect it to the ports behind the slate. (update: thanks to "COWA" from the HP support forum, this behavior happens when you enable USB debugging. Disable USB debugging and the side port should work as the other 2).
- Sluggish performance? sometimes when you switch between tons of apps, you'll get a slow performance (that's what happens when the vendors only install 1 GB of RAM). A simple solution would be to press the multi-box (on the bottom of the screen, the right button), and swipe down any app that you're not using. Android is doing it's best to manage the memory, but Android is not magic...
- root Hackers - Be careful with the Slate's boot loader! since HP rewrote the boot loader, you can easily damage the boot loader if you install wrong 3rd party recovery image (currently there aren't any, neither CWM or TWRP for the Slate 21). If you'll damage the boot loader, you'll be stuck in whats called "APX mode", which is a low level and it's being used to flash firmware to the nvflash. This is very tricky if you don't know what you're doing and could easily leave you in a hard-brick situation!