No, the paid for lounges are not that great unless you plan to drink 15 quids worth of Orange juice. Lots of shops in T3 so go and have a look at some nice shiny things and spend the money in Starbucks.
The pay lounges are generally tired & poor compared to the airline specific lounges. When the airport is busy or you have a long wait they are OK. But £15 for a couple of drinks & a bag of nuts is a bit steep to be honest.
