I used the Mastercard lounge twice last year. I would say it is good for a third party lounge, there was a decent selection of hot food (my brother who doesn't travel club or uses lounges often commented the food here was better than the BA Galleries 1st at T5) and a wide selection of booze including Budvar beer. Only thing to add not related to the lounge, is the queues at gate security was horrendous during my last tip in December, a friend also experienced similar issues a few days prior.