Best Flat Roof

I got three quotes from very reputable roofing companies (and well reviewed here on HomeStars). All 3 were within 1k of each other and the reason I went with Best Flat Roofs is because:
1) Oleg provided me with a quote on the spot (after 10 min of calculating the quote and writing the paperwork)
2) Oleg is very knowledgeable about roofs - he did not recommend putting breathers or vents on my flat roof (further online reading confirmed that you don't need those for flat roofs without attic). The other 2 companies were offering to put vents which increases the cost and not to mention possibility of leaking.
3) Best Flat Roofs is perhaps the only company that does not require any deposit upfront and the full amount is only payable after the complete work is done to the satisfaction of the customer. I like that.

I think you can only find out if the company is great based on how they deal with issues. In my case, there was a slight miscommunication/misunderstanding: they replaced the shed shingles, however they did not replace the plywood underneath as per my agreement with Oleg. I was not home that day, so I phoned Oleg afterwards and he called me back after consulting with the team and immediately offered me either a very generous discount or that the team re-do the shed roof. I chose the re-doing of the roof as that was my original idea. The whole resolution was very painless and there was zero frustration on my part (if only all issues were resolved this way). A week later, they re-did the shed roof and replaced the plywood.

Regarding the work: they offer 10 year warranty, though the roof will probably last 15 years. The team was very professional and cleaned well after both the flat and shed re-roofing. They also took out all existing roof layers (I think there were 3) and installed new isolation (I highly recommend). On the flat roof they fixed the slope so the water doesn't pool on the roof (important for flat roofs). Additionally they cleaned eavesthroughs of leaves although that was not in the agreement.

One more thing: I did not wait for long once I chose them to do the roof. They started work in a few weeks (this was in Nov/Dec, so the weather was not that great). The flat roof took less than a full day and they did shed on another day.

All in all I had a very pleasant experience and would definitely recommend them without hesitation.