The general consensus is that it isn't worth it unless you have the current boss on farm and know exactly when your Cooldowns/Bandit's Guile are going to line up, as well as how often you'll see them go up. Better to pay attention to other things instead, whether they be encounter-specific or rotation-specific (as Combat is about more than RvS > SS > Evis anyway, especially with Heroic/Warforged Assurance of Consequence).
As for the "Rupture is 10 energy cheaper than Evis" argument", that is why DPE (damage-per-energy) calculations are made. Even taking this in account, we're looking at a situational 0.5% gain at most. Also, once your Haste & Mastery reach ridiculous levels, the theoretical tempo gain from paying less energy on the finisher is almost irrelevant.
It's like Blizzard wanted to remove Rupture from the rotation, but couldn't bring themselves to do so mid-xpack with all the elitists breathing down their necks