$50 for 5 years to save you time in the customs lines at the airport? Sign me up!
The process is a bit slow - I applied online and booked an appointment. At the time I applied, appointments were for about 4-6 weeks away. I had to cancel a couple of times because life happens, and I can't always plan that far ahead! So, even though I applied in November, my interview was in mid-January.The interview was straightforward and my card came in the mail about 2 week afterward.
I've had my Nexus card for about 2 years now and I love it, but you have to know when it's better to use it, and when it's best to just line up and wait. Know the rules, and don't try to break them because you'll get your Nexus membership revoked and possibly be blacklisted at customs - not worth it!
Here are my rules of thumb:
1) If you are carrying any kind of food, and have declared it on the customs form, don't use Nexus. 99.9% chance you'll get sent into secondary customs and it's not worth the wait or hassle. (Although, some days it's faster to get sent through secondary than to wait in the regular line at Pearson... use your judgement).
2) If you've gone over your duty-free allowance (i.e. you spent more than $750 CDN after being away for over 7 days).
In these instances it's better to line up, explain to a customs officer and the worst that can happen is that you'll be sent to secondary search, but most often you'll just get waived through if you explain yourself.
I find I don't use the Nexus line going into the US too often, but it's saved me a lot of time coming back into Canada from International destinations. With the long waits for checking in baggage at Pearson these days, having Nexus has saved my butt couple of times when I almost missed my flights because the customs lines were so long.