Thanks for the info inhibernation. You see you are just as informative as us!! I got a power plate (I think you recommended that too!) What your doc says seems to make some sense and I am always impressed when they say they've looked at new research, as often they are stuck way in the past.
What he says about standers also has a sense, but what about the hip joint not forming a proper hollow if they do not have weight put through them, even in an artificial setting like the stander. Its so difficult as you only get one chance to do the right thing, and if its not right......?
wrt the splints. We are very interested in Anat Baniel Method and on her page she recommends a dr who makes splints which leave the ball of the foot and toes free for sensory info to get through as splints desensitise the foot, (makes sense but in the US) she prefers a child not to have them but says its down to the childs paed. She is also a big fan of floor play to promote normal crawling and locomotion, even though things take much longer. The muscles do stretch and grow with normal usage as your doc says, and it is interesting to learn how these messages from the brain are distorted in spasticity. It certainly seems right if SDR works so well in SD children and breaks up the incorrect signals (I dont believe it is the intensive therapy afterwards, as our friends son had intensive everything from an early age and the spasticity worsened as he grew - is is waiting now on SDR!)
I'm really surprised you cant find more SD children as it is far more common than athetoid or ataxic CP (10-20%), spastic is around 80%. We think DGS is a mix of athetoid and ataxic but has neither in the described form, no spasticity but fluctuating tone. We know a couple of SDs but no-one like the boy, he is supposed to be spastic quad but can suck his toe when relaxed! His neuro disagreed with his paed 
PS How do you get to hairys blog. I can never find blogs unless i stumble across them by accident, then hooked for ages!
MN and CP websites are definitely more informative that some drs!