Don't do it- read the fine print. If you buy the FSN package, they will still block out ALL programming that is sold in another package, like Center Ice or whatever they call their NBA package. You won't get games, only the other stuff.
That said, I have had a excellent time with DirecTv and Center Ice. Not sure what the complaints about the NHLN are... I haven't lost a game to it- usually they show the Detroit feed so after i switch the channel, it's all good, and I love the old games shown in their entireity.