I got 20 marks for completing this mission while the special Vault Shuttle event is on. As usually happens, there was little chance my pug team would have completed the mission if I hadn't been there to complete the side tasks.
Meanwhile, I got 60 marks for a badly noobed-up Infected Space Elite mission that possibly set the speed record for failing the optional, plus a Borg Neural Processor.
There is no way that doing Infected Space without the optional is as hard as Vault Shuttle, forget 3 to 4 times as hard as the rewards would indicate. This is the hardest mission of the Romulan branch and ought to be rewarded as such, especially if you want to sell $5 shuttles.
(It doesn't need to be easier. We have plenty of quick, brainless Romulan mark missions. I'd rather it got harder in the first and third rooms and provided STF level rewards.)