I have all my flying bases magnetized. For me it is mostly about fitting everything into cases for transport. It makes that sooooo much easier. Also, the socket on my very first skimmer, a raider, loosened so much that the model would flop forward immediately when I put it together. I thought about adding some glue to the ball end to tighten the joint but didn't want to risk overdoing it. The magnet went on easily (I cut off the top half of the ball to give the magnet the max gluing surface) and I love how simply it goes together and comes apart. I magnetize everything on a flying base now.
The magnet also makes it very easy to make a skimmer into a wreck, simply remove the base and set the skimmer down.