I think it's worth it. Especially now I spend more time at the airport than I used to.
The other option is getting Amreican Express Platinum. Althought it only allows you to use CO or NW clubs on the day you fly with the airlines, it has other nice benefits. (2 for 1 on international business/first class, special events, specail restaruant reservation). The cost is $300.00 a year.