I just got the RunCam2 a week ago, and they neglected to include a battery so I cant speak to much in the video quality/software department yet. As to its physical appearance, it is somewhat larger which I dislike, but I think it will be nice to connect it to my phone and preview the footage on the field right before launch. It also has a quickly replaceable battery and available external chargers, so if you do a lot of flying this will make it a very attractive option.
The 808 series isn't really designed to be 'mounted' to anything, and the QC on sizing is occasionally bonkers. I've had a handful over the years from customers which for some unknown reason wouldn't fit the shroud without modification. There are also some very similar models available for purchase which can cause confusion on which one to buy. I think they are still very good value at half the price of the mobius/runcam. There is no reason to buy one of these if your budget allows one of the other options.
The Mobius2 seems to have been a short lived product, and are fairly uncommon at this point. It works well, but was quickly superseded by the Maxi. If buying new I wouldn't consider it anymore. I think I've only used mine once...
The Mobius Maxi is my current favorite for 3"+ rockets. Comes with the wide angle lens standard, and seems to take good video with options for 2k or a high framerate.
The Mobius Original (Sometimes called Mobius Pro Mini on amazon) is the standard in the community. I sell more shrouds for this camera than all others combined, and it is almost always available on amazon with fast shipping. It has proven to be a bulletproof all around camera. I have used this camera more than any of the others.
The Mobius Mini is a perfect camera for smaller rockets as it has a smaller cross section. Otherwise functionally identical to the mobius original, though with only a 30min battery life. There are two versions of this camera out there, one with a hard case and one with an updated semi-rubberized case which feels like the Mobius Maxi. Both are reported to fit the same Mobius Mini Shroud. I don't have one of the updated cameras to verify fit personally, but if anyone were to have a problem just email me and I will get it sorted out.