It is better than 3.5 Sudden Strike. At 17th, level what's going onto the attack besides weapon damage plus Sneak Attack dice? There's no Booming Blade synergy because Sudden Strike requires the attack action. There's no GWM. Sharpshooter is a possibility, but you'll need advantage from an external source to help with the penalty. Using the ranged weapons a rogue is proficient in, that's still only going to be 1d8+10d6+15 on 2 targets for an average of 54.5 per target, or 109 in one turn, assuming a light crossbow with Crossbow Expert. That's nothing to sneeze at, but in the scope of everything that can be done by players at level 17+, it's hardly game-breaking.
If that damage could be directed at the 1 target instead of 2, I'd be more inclined to say it obsoletes other rogues at that level.