I decided on Artificer after originally planning on Tempest (purely because of the 'throw all traps' skill for Elemental mines I used in Multiplayer). I play as an Archer and it seemed the better fit of all 3 Rouge specialisations. Those elemental mines have saved me many times as mobs come through my tanks. But also, catches out those stealthy invisible enemy rogues who like to flank. Plus the satisfaction of running up behind my tanks and throwing all the mines in front of them, right on a group of mobs and they all explode in a shower of elemental damage is pure joy.
Cool down for Elemental mines is 24 seconds. Seems an eternity at times, but the key is to do it with full stamina as the 'throw everything' skill increases how many you throw out.
Then when it's time to fight a boss, I use 'Hail of Arrows'. Hit stealth (for 50% bonus damage) then hail of arrows then let loose with Full Draw as your opener. Awesome damage.
FYI Hail of arrows only works with skills from the Archery tree. So not worth it if you are a DW Rogue.
I use the Fallback plan skill in MP, but haven't seen the need for SP as my tanks normally have aggro, if not my traps will be my first line of defence, followed by stealth. Plus I need room in my skill bar for 3 archery skills, to make the best use of Hail of arrows.
I'm glad I went Artificer over Tempest for my Archer.