I am based in Sofia (I sinned in a previous life I guess!) and often have to travel back to the UK.

A recurring theme is as follows :-

OK charge 400 Euro economy 700 Euro Business
BA charge 900 Euro Economy 1400 Euro Business

OK offer me automatic upgrades, so no need for the business fare. Never been upgraded on BA - stopped asking 10 years ago!!
OK's business seats are proper business seats, with proper legroom. BA very variable.
OK's food is great, although I fly with them so often its getting a bit repetitive. BA variable.
OK's staff treat me well on the aircraft. BA extremely variable.
OK give me silver and gold status on cheap flights unlike BA generally.

Downside with OK is that I have to transit in Prague (not a disaster). Lose 3 hours max to save at least 500 euro!!

I am a BA shareholder I have to add so I have every incentive to fly BA!!