With the demolition of the original Durtie Nellies on Sanlitun Nanjie, the Durtie Nellies by the Third Ring Road at the Lufthansa Centre is the only Durtie Nellies.
Durtie Nellies is like any Irish "pub" around the world outside Ireland. It is stacked full of Irish-themed memorabilia, including in this case a hand-painted portrait of Michael Collins which should keep the British expats happy (errrr!!).
Durtie Nellies is a bit unusual in Beijing in that it is generally free of the "night-life" found in other business expat visitor-laden haunts. This makes it a pace where you can sit back and eat, drink, read, listen to the music on your own without being hassled.
If you like big, noisy crowds, Durtie Nellies is a bit hit-and-miss. The pool table and the darts board brings in groups which livens the place up, and Durtie Nellies seems to attract locals as well as expats (unlike the other similar bars) which makes it a nicer place.
The food can be a bit hit-and-miss as well, and I have had the worst Irish stew ever here. Normally the food is acceptable, if a bit insipid.
Dress Code It's a mellow place rather than a raucous pub, but it is friendly, you can meet locals and expats easily, and it is "comfortable".