OP I'm not sure if you are still checking this, but I've gone Subtelty for leveling. Jumping out of Stealth and critting with ambush for 3/4 of the mobs health is hot. Yes, it kind of sucks with adds... there goes my burst damage potential on the 2nd mob, but S&D and I'm ok.
Now that I got "all" that I basically want with Subelty for the moment I've been branching off for the DW OH extra damage, as well as the +hit damage, and of course Close quarter combat for the extra crits with dagger/fist weapons in the Combat brance. I've also just started with Malice in Assassination branch.
Gyfhidden's armory I made my mind up a long time ago when I started collecting my BoA items, that I'd go dagger Rogue since my BoA daggers scale as I level. Loving it, and very very very little downtime. I don't eat between fights, rarely bandage. Positioning of mobs can get tricky, or you have to be patient, but it gets the job done lol.
So far, loving the spec. It might not be optimal for raiding or instance (since until Tricks of the Trade, Ambush from stealth is a no-no), but as they say To each his own.