Hi,
There are some major differences:
1.
Sask - you work for 6 months, if you have studied in Sask based educational institute and then apply for Student SINP, while students of other provinces now need to work for 1 year. No priority given to students of Sask. for processing of PNP applictaion, and hence MAY take longer time. MAster's and PHD students of Sask universities get direct PR, provided they meet some given conditions.
The job(for which you gather 6 months or 1 Year work experience) can be Any part time, co-op, on campus, off campus jobs...as long as it is 960 hours (for 6 months) and 1920 hours(for 1 year), and then at the end of completion of required hours/months... One MUST have a full time job offer,. hence a hell lot of flexibility to change jobs and employers. You just need to collect evidence of working there.
2.
Manitoba - Irrespective of any province you come from, as an international student..you will have to work for 6 months in ANY full time job, BUT priority for much faster processing of MPNP applications given to Manitoba students. No special PR scheme for University students.
The job has to be a Full time job... right from the start... that too under a SINGLE employer for 6 months, and while working under that SAME employer..one need to file his/her MPNP application. Hence, no flexibility to change jobs..have to work strictly under 1 employer..and honestly some employers may try to exploit/take benefit of this situation, since the student's MPNP/PR is in that single employer's hands.
So, as an international student of other provinces, even though one may need to work for 1 year in Sask (as compared to 6 months in Manitoba), there is much more flexibility in SINP. And it's better to work for 1 year in SINP, rather than being stuck with single employer(unless it's a good job), if 1 has a 3 years PGWP. As a Sask student.. SINP is best. So, this is my personal opinion. Rest upto you to decide.
Links:
http://www.saskimmigrationcanada.ca/student
http://www.immigratemanitoba.com/how-to-immigrate/international-students/
Apart from Sask. and Manitoba, in reality... Quebec has the EASIEST PR (direct CSQ)... ONLY if one knows intermediate level FRENCH (i.e DELF B1/ or studies in French medium), and studies certain type of courses such as Diploma level of min 1800 hours/2 years(1 or 2 shorter diplomas combined) and above in colleges or Bachelor degree or Master degrees and above in Universities..
Best of Luck.
***All opinions expressed are purely personal, and pieces of information mentioned are to the best of my knowledge... You should consult other sources too.