sixspot I think you have lots of good advice here, it is so different from one place to the next how children are treated...
I have a ds similar age to yours(no dx yet), he was 4 in May, he has progressed so much since April, who could have predicted that? My ds's Paed asked what we had done to him for him to have progressed so much since he last saw him in September.
The SALT comes for home visits(an hour and a half weekly) and sees my ds briefly at school maybe for 15 mins(he is at ms nursery in Scotland), she comments on how much more talkative and different ds is at home than at nursery.
my ds gets one to one support at nursery (he is there 3 x a week for 2.5hrs a day), there is an autism base at the school which his nursery is attached to, it is no longer described as an autism unit, just the base, because children are included in class and go to the base as and when they need it, from what I can gather.
My long winded way of getting round to making a point? I think you know your ds best, but like others have said here, go and see what is on offer... speak to ed psych?, does your ds have an early years support teacher? (not sure if they are available in every area?), parent partnership?
Ds's early years support teacher is fab, he only sees her weekly but she knows her stuff, I trust her completely, getting other opinions is vital.
the paed and nursery have suggested we keep my ds back a year, so he won't start primary until he is 6 (usually 5 in Scotland), but I am going to wait and see, I have another full year of my ds at ms nursery to see how he is coping, but I am also going to ask everyone who has advice to give what their opinion is too.
there are no special needs schools in my area, so it isn't really an option for my ds, we have ms. or home ed to choose from.
I hope you don't mind me giving my pov, I always like to hear about how others are coping, I hope your ds gets the right school for him, ms or not!