Reading the NEXUS website it says that not all permanent residents have to be in the country (Canada) for three years to obtain a NEXUS card.

Can anyone tell me who the 'Exempt Permanent Residents' are?

8. The current wording of the residency requirement in paragraph 6(f) does not allow for the following groups of persons to be considered eligible for the NEXUS program:
Permanent residents of Canada or the United States who are the accompanying spouses, common-law partners or dependents of Canadian or American citizens serving abroad at a Canadian or American diplomatic mission or consular post;
Permanent residents of Canada or the United States who are serving overseas in the Canadian Forces or United States Armed Forces;
Permanent residents who are the accompanying spouses, common-law partners or dependents of Canadian or American citizens or of permanents residents of Canada or the United States serving overseas in the Canadian Forces or United States Armed Forces; and
Internationally adopted children that are permanent residents in Canada or the United States, but have not resided in Canada
CN12-020: Proposed Regulatory Changes in Support of the NEXUS Program

Already answered by FL

NEXUS - Amendment to the Three-Year Residency Requirement – You may now qualify for NEXUS membership

Thanks all! So it sounds like if you are living here with a straight forward job and no complications you can apply. Excellent.

Not worth the hassle.

It depends on where you live and how you use it. Many are simply getting one to use for domestic flights to avoid the long line ups going through security.
As you get Global Entry privileges along with it you can use the US kiosks when flying into the US from anywhere in the world and some of those line ups for US Customs are horrendous.
Ask the drivers crossing at Douglas or Pac Highway if its worth it or not.
Some people are under the impression that if you have a NEXUS card it exempts you from going through Customs which of course is BS.

I wish we had NEXUS years ago. Crossing the US/Canada border at The Whirlpool Bridge is a breeze...straight through...no waiting. We've sometimes been waiting for 2 hours at the Lewiston crossing. Flying in and out of US and Canadian airports is so much easier and faster. Well worth it IMO.

But would a UK passport holder have the same experience? Don't they need some origami in their passports when they visit the US across a land border? And queue for that?

I don't know...that's a question for FL.

If flying you would still need the ESTA and if driving the I94 waiver but if the line up is an hour or more just to get to Customs you by pass that and just get referred to secondary for the I94 so could be quicker if nobody waiting inside.
Perhaps that might entice a few to take out Canadian citizenship if eligible

So in normal circumstances, you have to be a PR for 3 years before you can apply? or just a "resident"?

A permanent resident ie one who has landed. Does not apply to workers, visitors or students who are living in Canada as temporary residents.

Worth having imo, has saved us a lot of time at both border x and airports. However, on occasion the NEXUS booth at border X's has not been manned (Staff shortage's?) meaning a long wait in the standard line up. Nothings perfect eh!

Damn, oh well...

This would save me so much time, I'm never out of the friggin' airport and although I can use the Air Canada priority line in Canada, i'm snookered for going to the states and have to wait in those ridiculous lines