Apparently wanting them to rerun the Elusive Targets for people who missed them, but still keeping the whole "you get one shot at getting them" element so that those that would be playing it for the first time could unlock the rewards while still having the pressure to finish it successfully and even more pressure to do it with an SA rank. Some people are just fine with others not getting to even have a classic looking 47 suit since they decided to only give a gloved version of his suit (or three) as rewards for ETs.
Outside of that, I think most of my opinions are rather similar to a lot of people. Blood Money is my overall favorite mostly because it's the game I started with though it isn't without faults. It's a bummer that every mission takes place in the US except for one mission, A Vintage Year. In that regard, the previous games were better for having the globetrotting angle.
Silent Assassin is amazing and significantly tougher to get into but because of the way the disguise system works, I found myself walking a lot more which felt so much more natural than running around like in Blood Money. Giving us a run button actually means I end up walking more than in Blood Money because it's hard to keep the thumbstick steady at the walking pace on a controller if there's no difference if you do or not.
Contracts has my favorite level of difficulty -- it's a little easier to the get hang of compared to SA but is also more challenging than BM.
I want the briefcase to come back in the new game and even for a dual version of the Silverballers since it's iconic. I never even really used the latter except for playthroughs where I just gun everyone down but still.
I think the new game actually feels like Hitman again and aside from some quibbles, I'm son happy at the almost complete 180 from Absolution. They took the best parts from Absolution (garrote-to-drag body, Contracts mode, the cover system) and implemented them into the philosophy of the old games (large open sandbox missions, generally just going after targets with a loose story to comment things and keep you interested, etc.)
Other than that, I'm sure I love most of the fan favorite levels and hate the hated levels.