Consular Processing ve. I-485 - Please advice

Will it save time if I opt for Consular Processing instead of filling for I-485 to adjust the status?

Will applying for both I-140 and I-485 be longer than only apply for I-140?

What's the pro and con?

Being Canadian citizen, can I choose to do the consular process in Canada instead of China ( birth country)?

Any advice/suggestion will be greatly appreciated!