I think your stat choice will be dependent on how you like playing the thief.
Since you’re going with D/D you have a good bit of condition damage from your Lotus Poison and Death Blossom. So if you like more damage over time and watching your opponents tick away you may want to give this a shot. Also Death Blossom lets you flip and evade attacks making timing it’s use important with harder creatures. Plus it looks cool. This is how I am currently playing my thief.
The D/D combo does seem to have potential for high burst damage if you go for power and precision. Your back stab out of stealth will do double damage if it hits from behind and Heart seeker strike can do big numbers on low hp targets. I haven’t tried a build like this but it seems to have potential.
Just remember to always take some defensive stats or prepare your utility skills accordingly. Nobody like a death thief.