1st any rogue can be good and is somewhat carried by a premade, or the right pug draw with arc mages, destros and hunters
when i play my 20s which i pug. the rogues that are not in the above situation, are twinked that cause issues in spec order: sub, assa, and combat.
sub spec seem to near equally build mast, crit, versa in the 25-30% the order is not set, but based on gear selected. extreme low haste. assa and combat spec i see high haste, in fights i see they are energy starved
as for poster on lifesteal, you may want to get situational swap out wpns with crusader, i have seen monks and rogues doing this, with all the squishes and patches that have messed up enchant mechanics, crusader actually procs on fast weapons, no longer has a 2ppm rate that it had in the first 10 years of WOW, and the heal was never squished and is larger than the original and boosted by versa. life steal was a van wow and TBC era rogue viable enchant. used to be 6ppm with 30 shadow dmg (30 fire at start of WOW, changed) and 30 health stolen, thru the squishes it lost around 83% of its original value, i think on a 20 it is 5/5 now, i can't imagine it scaling up enough to make a difference in a 20-29 bg