Shadow Assassin's Action is clearly better than Daggermaster's action, as the SA still lets you take your AP action and grants +4 to any attacks you make, not just a reroll on one (which averages to ~+4).
Precision is far and away better than riposte, at least until you're epic and can get a permanent 19-20. As a squishy rogue you're better off trying to avoid situations where they can hit you.
Dagger Advantage is only slightly better than a feat, while Bloody Evisceration is extra damage for about half of every fight.
Killer's Eye and Critical Opportunity are a wash IMO. They both have prereqs that are often hard to meet.
Meditiation of the Blade has to be activated and is a stance, so can't be coupled with other stances. It does an average of +1 damage per die, which means it'll take ~2-4 attacks for it to deal the same damage as your riposte. Overall it'll deal more damage in the fight, but it can't make an attack a near auto-miss. Advantage: Bad Idea.
I prefer Deep Dagger Wound to Final Blow, but it's close. Final Blow requires a bloody target, but makes up for it by targetting Reflex and doing an extra [W]. It's the ongoing 10 or 20 that I like about the deep dagger wound. That'll definitely make up for an extra [W], and then some if you crit and/or they fail a save or two.
Overall it's a wash. If I make a paragon level rogue and have to pick one or the other, I'll probably go with Shadow Assassin, but only because we're already had a daggermaster in our group.