Just the transcribed census dataDoes ancestry not have Scottish BMD's, just the transcribed censuses?
None of the above.Does it have Scottish OPR's?
Does it have Scottish Kirk session records or burial records?
A reasonable summary!It sounds as if it's of most use to people researching ancestors in England, Wales, North America and Australia rather than Scotland and Northern Ireland where most of my research is concentrated.
Best bet is to make a trip to your local library and see if they offer Ancestry access for free, so that you can see what you are able to access on Ancestry and if the records there will be of use in your research and decide from there. If there is no library in Ayrshire which does, then a trip to the Mitchell in Glasgow will enable you to access Ancestry for free. If not able to go into Glasgow, you can alwyas take out a pay per view short term sub if there are just a few things you want which gives 12 record views for 14 days for £6.95 - I do this sometimes if unable to access the library. You can see all results of searches in full that way, but you are limited to 12 actual record views, so best to save it up until you have a few things you wish to "round up"!
Best wishes
Lesley