Well I liked both of them for what they are. The atmospheres in both are different, but appropriate. ME1 had that feeling of wonder and excitement throughout. In it you fly around the galaxy to different worlds and see many interesting things. Shepard, while still formidable, isn't quite the "epic hero" yet. He's learning his way around and you see as he becomes more than just some human soldier. You're finding out about this dangerous force that is a mystery to most and slowly unraveling Saren's plan. ME2 on the other hand is quite different. Shepard is already a hero and a legend. He knows that the Reapers are coming and that its going to be a hard fight. Now he's just getting ready. He's assembling a team of the galaxy's finest to help combat this threat. This is why in ME1 most of the missions where story-driven while in ME2 the mission where mainly character-driven. The brighter, more optimistic atmosphere works for ME1 and the darker, more grim atmosphere works for ME2. I can see why someone wouldn't quite like ME2 as much as ME1, but try to understand why there is that difference. I'm sure that ME3 will have yet another unique atmosphere (my bet is on a mix between hopeful as you fight off the Reapers and desperation as you take losses from the brutal war).
As for the gameplay elements that were changed I'm a bit iffy on them. There were several annoying elements from ME1 that Bioware tried to deal with, which was nice. The only problem was that they didn't do a very good job of dealing with them. Annoying large inventory? Give them only two of every gun now. Long elevator rides? Replace them with long boring loading screens. Clumsy planet exploration? Have them just scan the planet's surface. Overwhelming upgrade choices? Now everyone has only 3 abilities. In the end I think they did too much. I hope that in ME3 Bioware manages to find that happy medium between the two. Decent sized inventories that aren't annoying to look through, shorter elevator rides, interesting planet exploration (similar to the Hammerhead, that was actually interesting), and a good number of upgradable skills.
As for Jacob, I never really understood why all the dislike for him. Sure he's not the most interesting, but I never found any reason to dislike him. He came across as a trustworthy guy who I'd want at my back.
As for the gameplay elements that were changed I'm a bit iffy on them. There were several annoying elements from ME1 that Bioware tried to deal with, which was nice. The only problem was that they didn't do a very good job of dealing with them. Annoying large inventory? Give them only two of every gun now. Long elevator rides? Replace them with long boring loading screens. Clumsy planet exploration? Have them just scan the planet's surface. Overwhelming upgrade choices? Now everyone has only 3 abilities. In the end I think they did too much. I hope that in ME3 Bioware manages to find that happy medium between the two. Decent sized inventories that aren't annoying to look through, shorter elevator rides, interesting planet exploration (similar to the Hammerhead, that was actually interesting), and a good number of upgradable skills.
As for Jacob, I never really understood why all the dislike for him. Sure he's not the most interesting, but I never found any reason to dislike him. He came across as a trustworthy guy who I'd want at my back.