I guess we're playing a different kind of game.

Latest example would be the newest expert dungeon, Cosmos.
Generally I would always pop sprint right before first pack of mobs so I have 20s duration and then just keep running trough (use AoE's to generate emnity on the pack as I run trough). In Cosmos I would keep running untill I'm blocked off by a closed door or gate where the mobs needs to be killed before you proceed (usually around 2-3 packs that is).

For an extra challenge I did not use Rampart or Sentinel (Shadow wall on my DRK).
I only used Reprisal, Arm's Length (best CD for dungeons imo) & Sheltron (Blackest Night on my DRK), Divine Veil & Dark Missionary (to mitigate party wide damage on bosses).
Did several runs on both these 2 jobs and always with pug healers (also had at least 1 off the three healer jobs), not a single wipe, not even on the first time I was there, altough the first time I messed up my sprint timings a few times because I did not know the layout yet and where mobs would spawn.

Expert (dailies) is the main way I use to cap tomes, I've been caping my tomes every week since the second week of ShB and I can count on one hand the times we had a wipe, also 90% of the times I went in alone and get DF pugs.

Seeing as the majority of DF groups do speed pulls I suggest you either 'learn' how to speed pull or you make your own pre-formed group with your own terms and then go in a dungeon and you can take your 90 mins run.