Blacklist is significantly better than Conviction. There are still some forced confrontations but for the most part, you can sneak past every enemy. The game gives you the most points for doing so as well. There are also side-missions, which I actual prefer to the story missions because they're more open-ended and don't have any cutscenes or other nonsense. Grim's side-missions are specifically tailored towards pure stealth players too.
Mark & Execute is still around and there are still some scenarios that were clearly designed with it in mind, but all of these scenarios can by beat by other means so M&E is still optional. If you really have no self-restraint, you can play on the highest difficulty which disables M&E.
I don't like the way there's 'convenient' checkpoint-like stashes where you magically resupply ammo and equipment. Is that standard now?
The stashes are disabled if you play on the highest difficulty.
Basically, if you want the best experience, play on the highest difficulty.