So gameplay in DA:O was fun?
In a few places, yes:
1) It had the best, player-configurable AI scripting of any RTwP game to date, which means that if you weren't much of an IE-style micromanager (i.e. constant pause/unpause/pause/unpause to micro everything correctly), you could set up your scripts and keep the real time flow of the game authentic.
2) Likewise, the degree of automatization worked well to your own playstyle. Again, if you wanted to set up scripts, you could. If you weren't a fan of all the skills and rotations that, say, a Sword&Board Warrior had to manage to be effective (compared to many other RPGs, where the Warrior is a very basic "I hit things" class), you could just set up your Alistair or Shale or whomever to work. The characters wouldn't completely shit themselves if you weren't babysitting them constantly, but if you chose to maximize micromanagement, there was reward at the end.
3) The fact that everyone had skills to use and manage made for some fun challenge in Nightmare mode, and it added replayability to the game because you could explore different paths with your characters. Want to make a full control mage? Go for it. Wanna try out a 2handed warrior? Sure. It's a more meaningful choice in terms of playstyle, most of the time; a teeny tiny bit more involved than "picking the best weapon choice for DPS or utility" (though obviously some choices are more optimal).
4) It was fun to discover spell combos and mixes and use them. It added a little bit of fleshing out to the magic system and the world (there's mages who document certain interesting interactions that take place between spells, and you can use their findings or stumble upon your own findings by experimenting? It's pretty nice)
5) I generally liked party control in Baldur's Gate and consider the boss-fights and enemy adventuring parties to be the most fun in that game, so I generally liked DA:O combat, too - though it doesn't have nearly as much great encounter design and there's a fair bit too many trashmobs.
6) Plenty of consumables to use, and many of them are craftable or fashioned to be fairly mundane in use, which means party resources weren't restricted to wands and magical potions. It's a nice touch, and once again gives more options to Warriors in fights where the physical damage or tanking isn't useful.
Neverwinter Nights - a game which I really, really like - in comparison has had some issues in terms of control and counterintuitive mechanics. Want to make a summoner? Well, your summons, familiars and henchmen eat your XP, so it's usually a long-term disadvantage to employ them, or you have to play around with dismissing your summons and familiars before you make a killing blow. Hiring a full spellcaster companion was also a crapshoot - Half-Orc Steve Blum and Edgy Dwarf are best companions because they play well into what AI does best, which is being a meatshield; likewise, Cleric Linu or Bard Deekin/Sharwyn are mostly fairly simple martial heroes that have some utility spells on hand to round stuff out, so they are never an issue either. Tomi the halfling Rogue was also not bad for certain playstyles where you could be the meatshield yourself or set up flanks. But try playing with Sorcerer-emphasizing Xanos or Boddyknock Glinckle, and you will see them opening a big fight with casting Mage Armor or casting AoE on top of you, engulfing you in fire while licking the - incidentally - resistant enemies. It's the old "Burst Weapons + Ian" volatile alchemy mix all over again.
On the other hand, though, I never had an issue with controlling any Player Character, even spellcasters, in NWN, because the hotkeys are generally pretty good and I mostly used the radial menu for out-of-combat or niche stuff. NWN supports arena PvP, so if you can handle it in World of Warcraft or any other game, you can probably handle it in NWN. It helps that bonus hotkeys are accessible by holding Shift and/or Control. I don't, at all, think the Interface is bad or unwieldy.