McGill VS UCL (University College London)

Hi all!
As the title may have already suggested, I am an International student accepted into UCL and McGill for Mechanical Engineering. UCL offers me a joint degree with Bussiness Finance and masters in 4 years whiles I can major in Mech and minor in finance at Mcgill in four years for bachelors.

Through my research I have found that UCL has stronger employment opportunities and competitive activities, however, I have also come across low student satisfaction rate for Mech.

If someone could please elaborate on this. like how bad is this and what exactly is it?

Also, I wanted to know the difference between student cultures of UCL and McGill?
I am looking for an enthusiastic and supportive student body ready to make a difference.

What I am honestly not looking for:
A culture that is too stressed, and soo competitive that people are pulling each other down!

Thanks guys for all you responses in advance! <3