I like both hotels.
In the summertime, I would choose the Bayshore for the reasons previously stated. Fantastic location to really experience what Vancouver is about.
The view of the mountains and harbour is beautiful. If you are a Platinum member it is worth choosing the continental breakfast option and upgrading to the incredibly varied and delicious buffet (My favourite hotel buffet in Canada).
The shopping district is not very far.
Either way you can't make a bad choice.