From my experience recently, radar performance seems like hit and miss. I almost blind in the Mirage. Its inconsistency makes it hard to make a report. For example, I could not detect again a target that I had previosly soft lock (in tws) right in front of me untill it was too late. And the new symbol quite confusing.
Regarding the magic, RB made some changes how it works to be more realistic. There's a sticky post about it. You have to select it via hotas. Pressing mag on PCA will make it enter search mode and not selecting to activate the magic.
Good luck.