Sun Routes
I think SOU has quite unique circumstances when it comes to the sun routes. There is definitely a market, after all, the city is located within a conurbation of 1.5 million people, many of whom are very affluent and therefore provide a relatively large demand for such routes - even at a bit of a 'premium price fare' needed with the use of smaller aircraft. Most of the previous sun routes were very well patronised, even in the quiet 'off season' times. Even my local postman used the Malaga route half a dozen times a year to go and play golf!
The problem is finding an operator with the right equipment for the job!
There's no getting away from it, the emb 195 is the ideal piece of kit for the rather unusual and particular set of circumstances at SOU, and few operators have these to hand.
Volotea with their B717s would also be perfect, but as they don't have bases in Faro, Malaga or Alicante, it would involve some quite complicated scheduling to provide sun routes to and from SOU. The only hope really I think is a change of heart by Flybe, or Volotea basing a 717 at SOU for the season - both of which I feel are very unlikely.