Ill try and give you my best personal and professional opinion with no bias, but it will be tough.
I am going to leave out Mobius from the comparison because I don't know enough about them to confidently give advice.
Street Guardian over Lukas,
-First and foremost support. I don't know of any other manufacture (in any industry) who personally provides such personal, quick, effective, and accessible support. Moreover there is a entire team of us who are there for support. None more prominent then Jon from Peir28. You can be sure that if you have any question or problem, that it will be answered and resolved the quickest with Street Guardian.
Of course we provide great support with Lukas too. However its honestly not at this level yet
-Secondly if you are looking for a camera that you can set and forget, and maybe not even notice the SG966GC or SGZC12RC are the top of the top for this.
-Video quality is the best out there I have seen yet. They make no sacrifices when it comes to this.
To summarize. Street Guardian has focused, designed, and manufactured their time on provided the best product they can from the basics up. Only developing a new feature when they can do it right. Never sacrificing quality, and user experience for a nice to have luxury like that Lukas offers. The have and will always put the basics first.
Lukas over Street Guardian
-Tons of useful features built in. They are fully loaded cameras.
-You have automatic parking mode. The camera knows when you park your car. It automatically goes into a parking mode which is essentially a motion detection mode. (The Street Guardian line up has a motion detection mode too. However you need to go into the menu and enable it every time you park, and disable it when you drive). The Lukas will then capture and differentiate motion and impacts. Even better, you can choose from a grid 4X3 grid where you want the camera to notice motion. This allows you to tell the camera to ignore say the busy street that it sees in the upper right conner.
-Built in adjustable low voltage cut off function.
-Dedicated Lukas Viewer computer program to view your video along with the GPS data, 3axis G-sensor data and if using OBD2 data. Along with a settings menu so that you can adjust anything you want from the comport of your computer, and not on a small screen.
I could probably go on. But lets leave it at this for now.