I think that my experiences are a bit different to a lot of the posters above, except maybe Broomstick Pilot.
I learned initially in a very radio-intense environment (actually just plain intense, along with a fairly sadistic RAF QFI who hated students). I couldn't cope, and as a result failed by UAS course.
Determined to learn to fly whatever, I went and paid for lessons in an environment which was (not planned that way, just happened) totally non-radio. I found the deletion of the radio requirement very helpful, and did a lot of help break down my loss of confidence with the RAF, and turn me into a half-decent student pilot.
I *then* had to change school (work moved me to the other end of the country, not anything wrong with the school), to one where radio use was mandatory. Having previously soloed in a non-radio environment, I'd got through the barrier of learning the basic piloting skills, and then had spare capacity to learn to use radio as well. This helped a lot.
However, realistically most people can't do this - the majority of students will rarely have the opportunity to fly in a totally non-radio environment, let alone get to first solo without having to talk to anybody. Nonetheless, I think personally that there's a lot to be said for allowing a student pilot to crack the basic handling skills of the aeroplane, and then introducing radio after that: this certainly worked well for me.
G