Ok Got the strap yesterday, is a step up from the stock, seems sturdy enough, easy to fit over the speaker sides in the headset just like the original, good fit and comfortable at back of head, easy to adjust head size with rotary control. Lack of any foam at top of head doesn't make any difference to comfort. Still feel some weight of the headset on face so need some slight adjustment by moving headset to get it more comfortable.
My ideal headset with strap would be one that allows the whole headset to seemingly float in front of eyes, with weight distributed evenly all around the headset and strap. I think maybe if there was a headset with some of the electronics all inside headset and strap unit, this might allow for a more even weight distribution all around. I'm sure that in future the headset design will change to get the whole contraption more comfortable.
Obviously If I had a whole selection of straps to try on I would do so and get the most comfortable, but I'm not convinmced there is the perfect strap, its a case of buying what seems a decent strap and sticking with it.