First of all, what type of engineering are you going into? I too have toured McMaster, Waterloo, and UofT.
Quite frankly I was entirely unimpressed with Waterloo's engineering facilities, and the university as a whole. Their buildings seemed old and run down, and there machinery looked like it was WWII era. Im interested in electrical engineering, and when they showed me the supposedly "state of the art" WEEF (sp?) lab, my dad(who is an electrician) told me he had more advanced equipment in his garage.
Perhaps I didn't see the best of Waterloo's engineering facilities, but needless to say I didn't even apply there.
At UofT, I didn't see much of their mechanical/civil engineering facilities, but their facilities for electrical and computer engineering were pretty impressive.
To be honest, if you toured the Hodgkins engineering building at McMaster I think the tour guide must have not shown you the nicest stuff. From my own personal tours of Waterloo and UofT, I saw nothing that came close to the equipment in this building. I was talking to one of the mechanical engineering professors at Mac and he said the equipment there was some of the best in north america.
As for jobs, Waterloo and UofT do have a slightly better reputation than mac (But I'd say mac isn't far behind these two...it probably has the 3rd highest engineering rep in ontario), but because all engineering prgrams in Canada are accredited by the same people, no university in particular will give you a huge advantage wityh jobs.
In the end I chose Mac because of the university, not the program in particular. Any accredited university in Canada will give an excellent engineering education. What Ive been told is that you should genuinely base it on which campus you will enjoy living at the most.
Waterloo is an ugly campus and Ive heard they have no spirit (not to mention its a sausage-fest), UofT is nicer (right downtown Toronto), supposedly has better spirit and actually has some girls, but Ive heard its very difficult to get good marks here and since there are so many students at U of T, its easy to get "lost in the crowd".
McMaster, on the other hand, has lots of ladies (
), is a beautiful campus, has one of the most spirited engineering faculties in Canada, and still has an engineering proram with an excellent reputation.
Long story short, if I were you, Id choose Mac....but of course, there are lots of people who choose UofT and Waterloo and are still happy with their choices so its really entirely up to you.