We just got our eavestroughs replaced, including installation of that anti-leaf protection system (whatever it's called). I am extremely satisfied with the quality of their work; very solid.
I highly recommend North Shore, which is run by Darren and Angela, for three main reasons:
(1) Darren addressed an issue that we were having about icing on the driveway during the last several winters from freezing rain down our downspout and proposed moving the downspout to the other side of the house. It sounds obvious in hindsight, but no one else thought to propose something;
(2) The crew arrived on time, was courteous, professional, cleaned up very well after themselves, and even took a look at my neighbour's eavestroughs at our request and cleaned out a specific blockage that they saw, for no extra charge.
(3) Darren in his initial visit dropped off without asking a maybe 12 inch long section of an eavestrough with the leaf screen, as well as a swatch of the various colours that the eavestroughs came in. Again, sounds small, but the swatch allowed us to do a lot of colour matching for some other exterior painting we did to our windows, and the sample allowed us to get comfortable on how it worked (we put it under the faucet and the screen didn't stop the water, even though the holes look small).
Anyway, these things really made North Shore stand out. Hope this helps you if you are looking for an eavestrough contractor.