How often do you travel?
I got one before our Disney trip in 2011. So, no baggage fees for that trip. When the year was up, I cancelled my card, and DW got one. That took care of baggage fees for our trip in July 2012. In March 2013, I'll pick up the card again and have DW cancel hers. If you go without the card for 12 months, your considered a "new" card member and can qualify for bonus miles.
Thanks to the previous trips and the bonus miles DW picked up when she got her card, our flights to/from MCO next June cost us $40 R/T for both of us. When I get my card back in March, I'll use my built up miles for our rental car or for hotels (we're driving to FLL for a cruise, then coming back and touring NASA before heading home).
Assuming this all works how I have it planned, I'd say the card IS worth it, and we only take one trip a year.