Never bothered with newry myself despite being so close to it! (but I'm not a big shopper anyway and I get cheap booze anyway)
Though was in letterkenny the weekend and we decided to head to londonderry for the day yesterday, and my girlfriend did all her xmas shopping and said it worked out alot cheaper compared to down here - she's got a taste of the bargains yesterday so I reckon regular trips to newry will be on the cards as a result