Newish to this section: hello!
I have introduced myself before but namechanged since then as was outed 
I know this is really a question only I can answer but it's going round and round my head and need to vent / hear other thoughts please.
DS1 dx ASD age 2 and 1/2. Now 3 and 1/2. Not in preschool, never been to nursery or cm (MIL looks after him while we work PT).
Spent ages looking at primary schools for Sept. Found local one we like and feel could work for him - obv with appropriate support (ie 1:1 FT) School prepared to work with us, very understanding HT, other ASD child in the school with 1:1, have made adjustments for him so it seems they can provide.
Had applied for statement to consider nursery / preschool, which have now decided against. Decided to go for PT entry to school in Sept instead. (He is 4 in June so 'young' starter too.)
Been told the other day over phone that:
a) he was awarded 15 hours support for preschool / nursery (ie 'FT')
b) for sept they suggest we apply for the LEA ASD unit attached to 'local' primary school (actually 1/2 an hour in a car away) for Sept. With a view to spending 1-2 years 'assesment period' there to decide whether mainstream or Special School appropriate and help him integrate into school environment. They apparently have a good set up with sensory room, social stories, visual timetables etc Sounds ideal (apart from the travel and not being permanent, having to transition somewhere else later)
It's a bit of a surprise (IMO he's not VERY severe). So need to get my head round it a little.
Not sure what I'm asking people for here really: points to consider, experiences of ASD units vs mainstream with support? Just feel a bit boggled 