Got back from Madrid on monday (friend's wedding). Really nice place - we stayed in the NH Hotel at Coslada, which was actually quite good - friendly staff, clean environment, excellent state of repair etc.
Madrid itself is brill - lots of nice places to eat and drink, nice and warm at this time of year, and lots of cool things to see in the city centre (and we went there on a Sunday, so I suspect its even better on a sensible day).
However. We got there (and back) with Easyjet. They shouldn't be called "Easy" Jet. They should be called something else, like "How hard can you possibly make it jet". Check-in was actually good, and the cabin crew were above average as well - but the praise ends there.
They don't allocate seats at check-in (which is why it is so quick and there are smaller queues), however, this turns boarding into what can only be called a "stampede". The guy handling it at Gatwick dealt with this by shouting and screaming at people - not ideal - although it worked. At Madrid, they didn't even try, and just let people push and shove to get through. Rubbish.
Oh, and on the way there, they ran out of proper food (e.g. manky sandwiches) by row 8. Not good on an Airbus 320.