I have had a ready rig since day 1 of launch. I'm not using it in any capacity other than larping, my thoughts in no particular order.
If you have been lifting for years I would just straight up say don't buy the ready rig. The muscle in your pecs and lats combined with the taper of your torso will cause mags to tilt at odd angles and print horribly, this can be minimized by wearing the rig lower but this causes other problems. I tried 20 round mags with a more traditional ride height as well and that just made pulling mags from the rig a nightmare.
The readyrig makes me sweat horrendously compared to other larger chest rigs.
The elastic cells have no bungie retention, but that's not a problem unique to the ready rig alone. Sometimes you may find the contents of a cell squeezed out from the bottom up like a tube of toothpaste. In my experience the chance of yeeting the contents of a cell increases drastically if the cell is either too full or not full enough.
Reindexing mags is basically impossible all over the rig.
The pistol mag sized cells suck, glock mags are like a hotdog down a hallway and cat tourniquets maul your skin if turned inwards and catch everything if turned outwards.
Its a well made piece of gear and seems well thought out but I found it for the most part unusable mainly due to the shape of my torso.