Of course, the company itself is going to say nice things, but how can we be assured that we are NOT screwed over in the future after we have set up the device and then later realize that our BTC ended up getting stolen?
If you are really concerned about this (and you should be) then consider buying Raspberry Pi with an external harddrive. You can use RaspiBlitz. It's quite easy to install.
Here you can view the installation instructions and there is even a list of hardware which you will need. The cost is 120 euro (including a touchscreen!) which is about 150 dollars. Half the cost for a self-made and open source device. The only flaw is that you might not like using the command line all the time.