It's amazing how differently people play the game. I consider the radar is as defining a part of XMP as the classes, hacking, and sprint-dodge-jumping.
When playing the classic merc role of gen and deploy hacker, the only way to see which need hacking and to work out an optimal route to them is to study the radar.
For anyone defending, once in position (base, generator, or whatever) watching the radar is at least as important as the main screen.
Sure, an orthographic minimap could do all this. In fact it would make it all much easier but, in my opinion, would also make it not XMP.
A minimap is independent of your position so is fine in any corner of the screen. With a radar the centre represents your position (I don't know about other people but I play from near to the centre of the screen). ONS has a minimap, XMP has a radar. ONS is not XMP.
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