As with any kit take it slow and try as many different setups as you can until you find one that fits every aspect of what you are doing. Try out friends kit, try it at a shop, buy used until you find what you like. And then save up and get the exact rig you want. Your own body mechanics will dictate how easy anything is to do and certain aspects of some kit will not work for you no matter what you do.
I will say one thing for the double stacked mags though, if you are looking for cover at premium, every inch matters and having a really thick rig can get you shot in whatever part is sticking out, or if you are actually training to include the things like supine or urban prone, they tend to get in the way. Nothing like jamming mags or a plate into your ribs. Same as having to many admin or specialty pouches. This is my own practical experience of course and years of being confronted with common sense.
As much as with anything, just remember the training is more important then the kit. Armatures train until they get right, professionals train until they can't.
