I flew Scotairways back to my home town (Dundee) from LCY a few years ago and they were very good, admittedly.
My worry is that BA will always automatically have a market share on any city pair they operate. There are going to be lots of current Scotairways EDI/LCY customers who are BA frequent flyer scheme members and will switch to their preferred airline, unfortunately. And BA will be operating a jet as opposed to the, albeit very fast, D38.