I understand your concerns.
At our first appointment we were seen by Dr Studnik himself and a Specialist SALT, we were given a working diagnosis of Autism.
Assessment was then followed up by the Specialist SALT who visited my DD at her nursery (another setting - as required by the NHS guidelines). However this may not be needed if your child is obviously Autistic from what was explained to me.
My daughter displayed signs within our initial/first assessment, but they wanted to observe her in another setting to see how she interacted with over children her age, and also speak with her educators to find out their views and concerns. I agreed to follow this process for my own sanity.
Overall Dr Studnik was fine in my honest opinion and from my experience dealing with him. He was very calm, kind and understanding. He is very respected in his field, and as I explained earlier, our local CDC was more than happy to accept his diagnosis. They even wrote supportive reports to rubber stamp the diagnosis which really helped us.
I will admit though - it did take him a while to send over the final report which I found a little annoying at the time, but this wasn't directly his fault. He saw my DD during the summer holidays, and had to wait until her nursery was open to allow the Specialist SALT to assess her over there.
Specialist SALT assessment cost me £500 so altogether it was about £1050.
Both reports were 'merged' together and concluded with a diagnosis of ASD.
DK is equally good, well known and well respected, but I honestly went with Dr Studnik because of his availability. I also felt reassured that his assessments involved another professional who was there to see and review my DD face to face, which gave us some sort of reassurance as we were in denial and genuinely unsure if she had an ASD. I believe DK does the same, but instead asks for reports from other professionals/school etc to make up the MDT.
Hope this helps