Despite this being a series that went to seven games, three of which went to overtime (2x double OT, 1x triple OT), this series wasn't particularly close.
Philadelphia outshot Toronto 282-189 (an average of 40-27 per game, and ~60% of total shots), and outscored them 24-16. Part of this came down to Toronto's lack of discipline...they spent 83 minutes in the sin-bin compared to Philadelphia's 65 minutes, numbers reflective of their regular season play. Toronto's truculence seemed to get them in trouble, as they were outscored 5-3 with the man advantage, but even at ES, they were outscored 18-11. All three of Toronto's wins were either Belfour playing brilliant hockey, or Cechmanek putting in a horrid performance. There wasn't really a game in this series where they just outplayed the Flyers and got the win.
Also, Toronto was not nearly as deep of a team as Philadelphia, even if their absolute top-end players outshone the Flyers'. However, by the time the playoffs rolled around, a lot of Toronto's top performers seemed to be worn out or injured (possibly due to age - they were the 2nd oldest team in the NHL behind Detroit, featuring 38 year old
Housley, 37 year old Belfour, 36 year olds Lumme, Roberts, & Corson, and 34 year olds Svehla, Wesley, & Fitzgerald). Only 7 players on the roster were under 30, and only 2 players were under 25 (Kaberle & Antropov). The Flyers also had their share of older players, but aside from Weinrich (36), none were 35 or over (most in the 30-33 range), and they also had 10 guys under 30. They just had more youth, and were able to spread their minutes out, and trust younger, faster, fitter players with important roles in a long series with lots of long games.