I've owned several of them, and even had a double din installed in my Dodge Intrepid, which requires making a custom bezel to install it, since double dins will not fit into a stock Intrepid.
I've looked through the Seicane selection of Android headunits, and they were generally over priced and under powered.
I did a google search on them too, and Seicane had some horrible reviews, especially with quality, customer service and actually fulfilling warranty requests. It seemed they just ignored any requests for returning the product and getting a refund, most of the time.
Sound quality can be hit or miss. Most sound ok, but some are better than others. Only a few generally have the higher quality chips in their amplifiers.
Don't get me wrong, I am hooked on Android headunits, because they can do so much more than a normal stereo could do, and even Chrysler is now offering an Android headunit from the factory. I think Alpine makes their Android headunit.
Names like Kenwood, Pioneer and JVC have also jumped on using Android for an operating system, but they as yet rarely support the use of bluetooth OBD2 adapters, and generally want you to use your phones GPS for finding your way around.
The Android units found all over ebay and amazon almost always support both GPS and OBD2 adapters.
Any external drive you use, should be as fast as you can get, and not insanely large, because the drive can adversely effect boot time, also, do not get a headunit that is under powered for the version of Android it is running. Anything with android 5 and up needs more than 1 gig of ram, or it will be slow. I had a 240gb SSD in my Intrepid and it worked well, but hooking up a 1 tb drive made it take to long to boot.
You have to have the Android system format the SSD drive for it to work. For whatever reason, they never seem to like it when Windows formats the drive. You need to format, fat32, or Extended Fat32.
I suggest going to the XDA android forum and asking there for recommendations to find the unit that best fits your needs.
This is the one I am getting. It has been shipped, just waiting for DHL to deliver it.
It has no CD/DVD drive, but it supports storing music on flash drives, and, you could even install an SSD drive to store music and movies on. It does support USB CD/DVD drives, if one is needed. I can't even remember the last time I used a CD for music, so I will not miss it at all.