For expert dungeons i go ham with the first pull and if i see struggling healer or i die i take it easier with max 2 packs for each pull, a lot of casters are afraid of using lb on trash as well which makes trash take longer, as ive geared up a bit now (and no stancedance penalty) ive starting going into dps stance for trash as well with rotating CDs heavy ones first lesser as things thin out
We're usually less geared for dungeons early expansion i feel, later on we will almost outgear the dungeons on release. and since its still early in SB a lot of players are still getting used to their new abilities and learning their jobs.

For lvling dungeons i play it safe because gear can be hugely different for players here, you can see someone in the last lvling dungeon for SB in 270 gear because they dont buy/craft it and been unlucky with drops, so i rather play it safe there with 1-2 packs.