I'm often intrigued by these claims. I sway more towards the Airline in these cases but agree that if you are left out of pocket for an Airlines delay then the passenger should be compensated to a REASONABLE level.
So, knowing that most SSH flights land back in the uk late at night, I'm guessing you booked the next day off work?
Can I ask what costs you incurred due to the 4hr delay? Extra parking charges? Missed onward connection?
The £1300 paid to you, was it sufficient to cover additional costs? Or paying for the next holiday.
Just because it's legal, doesn't mean you need to take it.
I fear for the prices of my future holidays....