TN can do full time job too if you properly address your offer letter. Many Canadian working in U.S. full time on TN status, say more than 100,000!
The benefit of Canadian passport:
1. You can visit U.S. without a visa and stay as long as you want for pleasure (no I-94 issued, so you're never out of status). If you want to study in U.S. just get your offer (I-20) and come in to the school. You will get your F-1 status in minutes at the border. You're never worried about F-1 visa as people from China. U.S. exempts almost all kinds of visa for Canadian. No just B-1/B-2, F-1/J-1, H-1/H-4, that's all. Canadian never need to deal with U.S. consulates/embassies. No any other country in the world enjoys such a convenience! What else more do you want to get, man?
2. You can work under TN status and renew it indefinitely until you die (life long). Comparing to H-1, TN's advantages includes:
A. no time limited renewal, H-1 is 6 years maximum.
B. get TN in 15 mins when crossing border, this is very important for many jobs/employers, since you can come to work immediately, makes no difference to U.S. citizen/GC holder. But H-1 you may have to wait couple months to get USCIS approved.
C. No annual quota, you can apply anytime. H-1 has 65,000 limit annually. 2004 quota has used up in Feb, all foreigners has to wait until Oct 1 to get new quota, many people may be out of status in the course. But Canadian never worry about out of status in U.S. since they don't need visa at all.
D. You may also transfer to H-1 from TN if you're really like it, but TN makes you available to work at once and this is not comparable from any kind of visas. You may get GC from TN directly, unlike lengthy H-1 to GC method which most people did.
3. In order to qualify for TN, you should have a relevant undergraduate degree in the field of working. Although most of professions are on the TN list, but not all. So check the list before you go.
4. With Canadian passport you can travel more than 170 countries without visa, even better than U.S. passport. You don't worry about terroist attack, hostage. You get free health care and many social benefits more than U.S. citizen. Many U.S. citizens claim to be Canadian when travel outside (especially in middle east). They just fear, what a joke! In the contrary, Canada has friends all over the world! The country is peaceful and democratic, so good an image!
5. U.S. passport/GC are only good for employment. Nothing else can compare to Canadian passport. Even for employment, Canadian enjoy TN convenience. That's just next to GC, and better than all kinds of working visas.
So saying Canadian passport a kind of virtual GC isn't that wrong!
6. These days many people go back China as oversea returnee, a citizenship is definitely better than GC only. With citizenship you can stay whatever you want and go anywhere freely, but with GC you still have to use Chinese passport + visas everywhere and have to stay U.S. half year annually. Say an investment, spending 10 years to get U.S. passport and 4 years for Canadian passport, the cost and payback is much different! Instead of spending 4-5 years riskly and not sure if can get GC, why not surely get Canadian passport with all benefits/conveniences! Just treat it as an investment of time and effort, and calculate what you get and you pay wisely!