I am planning a trip to Canada in January but don't know whether to go to Montreal or Toronto. Any advise would be highly appreciated thanks.

They're both very competitive cities.  The women in Montreal generally ask for lower gifts then the ladies in Toronto.

Toronto has more of a corporate business foundation, and generally a larger upper-middle class population.  There are also more business travelers going through Toronto.

Why not do both? It's easy to take the train from on city to the next. Only takes 5 hours from downtown Toronto to downtown Montreal.