Going back to the OP on this thread. I used SEN recently and have to say it was a good experience.
Had a 06:30 departure. Security was fast. Shops are good. Fruit gaming machines down on departures gate level outside the mens toilets are naff and a bit stupid if you ask me - no need for them.
My only complaint being exiting car park 3 long stay. Prepaid on Holiday Extras but slipped the ticket in at exit barrier... BOOM... £168 due please!
Pressed the help button gave the chap my vehice reg and parking ref number and he let me out. Same thing happened on the two cars in front of me. Getting out of the car park took me 12 minutes in sitting there between cars in front and myself pressing help and going through the motions.
I've noticed this is the norm on any Holiday Extras car park advanced bookings. It's happened to me at Gatwick, City, Stansted and now Southend. I think there must be some screw up on the integration of Holiday Extras booking system to the airport systems. When I book direct on airport websites I never have this problem.