Why I didn't like Dragon Age:Origins as a BG fan
Not in any particular order, and am posting this from memory. It's been a while since I played DAO (only once), and I've been letting it sink in more especially since a couple other friends played it more recently and we've been talking about comparisons.
1) Railroady. The BG franchise is more sandboxy than DAO. People like me who enjoy more freedom in exploration will find DAO constricting and not terribly creative in terms of travel opportunities, immersing more about the world, etc. BGI allowed more random exploration than BGII, though I can understand why this setup would be confusing to some people (side-tracked by quests) who are trying to stick with the main storyline.
2) Cut-scenes: Fully voiced and animated cut-scenes reduced the overall amount of content they can fit onto the game disc, IMO. Text content is much cheaper to produce and you can end up stuffing a whole lot more into quests, dialogues, and lore. Others have mentioned this, and I totally agree.
3) While DAO NPCs are better "written" (only because they get a lot more voice acting so they feel more "alive," perhaps), that development seems to have gutted your own PC's dialogue options. DAO's dialogue options were all much shorter than BG's.
4) Scoreboard and bribery-based romance system: The number-based scoring and bribery mechanisms underlying the DAO romances, no matter how well-written the romances actually are, pissed me off to no end. Of course, BGII's basic romance system is number-based too, but it's black box and you don't see flashing numbers on your screen. The idea that you can do a quest that lowers your reputation/anger party mmebers and then BUY BACK PERSONAL FAVOR by giving a gift is particularly grating as well. The entire romance scheme in DAO screams "crutch for horny boys"! FFS.
5) To me, tactical combat in BG was actually tactical while DAO is a scythe through a zombie army. The problem I had with DAO's combat is that there are exactly three combat types in terms of enemy, all humanoid with no particular special abilities: melee, archer, and there's an offensive mage-like caster thing. In terms of special skills for each of these basic enemy classes, you'll see a few stuns and roots and stealth and such, but this variety is nowhere near having to maneuver your party against another party of mage-cleric-druid-fighter-thief-etc. with a much larger array of spell and skill options--never MIND the huge BG bestiary. The MMO-style LOS pulling was a plus for me, but that's all that really stood out in practice, that I can remember. Now, allowing any DAO party member to learn skills like poisons and traps was a nice touch for more tactical flexibility, granted... but the lack of tactically challenging enemies besides bigger/stronger/more things doesn't require players to figure that out. DAO combat, for me, was just masses and masses of the same enemy types. Armies. LotR style, I guess. That's impressive from a distance but annoying close-up when you're just mowing the lawn.
6) Side quests are just really short in DAO. "Side quests" in BGII were mostly involved complex chains that spanned multiple levels/maps and whatnot. I hate the MMO-style "I HAVE A QUEST" business, though I suppose that works for the DLC mechanism. I loved finding new things in BG-style games by accident on multiple playthroughs. The "quantity vs quality" comments about DAO in this aspect ring true for me.
7) Lore. While DAO's lore is just as interesting as BG's lore (not as much breadth, though), I really hated the interface when reading those lore bits in DAO. Just after picking up or viewing something like a statue, something will pop up on the screen and disappear a couple seconds later, forcing me to dig around in that idiotic interface--forgot what it's called. It was very clunky and kind of immersion-breaking to me, unlike finding a bunch of books in someone's library in BGI/BGII and just reading them like that. And relying on my own memory.
8) Expectation. This is my own fault; I'm basically angry at myself for falling for the marketing blitz around DAO--normally I'm not this gullible at all. But DAO's connection to Baldur's Gate was being used as a neon sign to beat up the target audience, so...meh. If I had gone into DAO with zero expectations in comparison to the oldies, then it would've fared better in my eyes, I guess.
Aspects about DAO I liked, mostly:
1) Moral quandary quests: These were generally well-done if a bit ham-fisted sometimes. I'm thinking about particular NPC-related quests, that is, where your dialogue choices had major effects; of course, BGII certainly had stuff like that. I don't remember DAO side quests much at all, though.
2) Actual spell/skill leveling system is interesting; it does allow for a whole lot more customization than the D&D 2 system, if we're talking about direct comparisons. As for D&D 3 with multiclassing and feats and whatever, I don't know.
3) Graphics? I guess so. But I honestly don't give a goat's butt about 3D engines and whatever, considering how much I laud PS:T and BGII (for different reasons).
4) Inventory system. I love this. Good job with that in DAO. I wouldn't mind this in all my games.
There are probably several other smaller points I'm forgetting, but whatever...