I have always loved that game. Brilliant gameplay, only I would have liked a newbie-mode without a timelimit.
But to shoot it all down the interface of PairsNG is really, really, really bad. It's ugly, it's big and above all: it is slow and unresponsive. I would go for pairsWB over a commercial pairsNG anytime, unless something serious happened with the GUI.
Sincerely,
-Kenneth Straarup.