Warriors may have the best offense in offensive rating (114.9), but Raptors are 5th (112.5).
Raptors have the better defense in defensive rating at 5th (106.8), while GS is 11th (108.5)
In net rating, GS slightly ahead (6.4 vs. 5.8)
In terms of opponents:
Raptors: Magic (108.1 ORtg/107.5 DRtg), 76ers (111.5/108.9), Bucks (113.5/104.9)
Warriors: Clippers (111.3/110.3), Rockets (114.8/110.1), Trail Blazers (113.6/109.5)
Raptors faced better defensive teams, while Warriors faced better offensive teams.
In net rating, Bucks were 1st by a clear margin, followed by Golden State and Toronto.
Finally, Raptors have home court advantage, which makes the series even closer.
I expect this series to go 6 or 7 games.