I bought mt T4.1 RTR. It came with some subpar parts (tires and servo for sure), but I had zero experience and the best parts in the world wouldn't have helped. RTR is a less expensive way to start and you can upgrade as you go. As far as learning/knowing your rig, as you break and fix things you figure it all out quite easily.
My next rig will be a kit for sure, but I'm glad I went RTR my first time.