Works great... just next to impossible to get. The web site has not worked for several months now under any browser running Linux (tried both Chrome & Firefox). All you see is an animated "infinity" symbol. I had to find a Windows machine to order this part.
This did not work for my Alienware M16 R1 (Intel) - it was showing as 240W instead of 330W in the BIOS.
I contacted customer support and they informed it was a chip issue, so they sent me one of the DELL Adjustable DC Adapter Tips free of charge which has worked wonderfully.
Nonetheless this adapter is a great product and the shape of the connector is also much better than the Alienware M16 R1's default one.