If you were to choose between this lamp and Magicshine EVO1700/1300 which would you choose? (I would like to install it under my garmin mount via gopro mounting)
That depends on what type of riding you do. The EVO 1300/1700 are better for road cycling as they have a sharp beam cutoff. If you're doing more mountain biking then the Ravemen is better as it's brighter and has a wider beam.
Yes, you can switch between high/low using a single remote button press or on the headlight itself. The only thing to note is that the headlight always goes to maximum output mode in the high beam mode when you switch to it as a safety feature.
Time remaining depends on the current run mode, so you don't know if 30 minutes left means you have 50% battery or 10%. That's why I'd prefer to have both like the Magicshine Allty 2500S so you have more information.