I played through most of the Prologue last night. Seth Green's character appears early on and is fairly jarring since his voice is so recognizable, but luckily he's only a minor character.
Personally, I liked the dialog wheel thing a lot better than I'd expected. It keeps the conversations flowing and movie-like, which is what I presume Bioware was trying to emulate. The one-word summaries have been pretty indicative of what the sentence it represents will be, and after a while you almost stop noticing the wheel all together.
Is it a great roleplaying game? So far, no. The leveling system is a bit watered down, and the storyline (at least in the prologue) has been completely linear. Your dialog choices can result in different NPC responses, but you still have to go on the mission. However, if you approach the game as an Action game with stats and dialog, it excels tremendously.
The class system has you choose from Soldier, Tech, Magic, Tech-Soldier, Magic-Soldier, and Tech-Magic. I went with Magic-Soldier, and obviously got a cross between Magic powers and weapons skills. Each power/skill has a ranking, and when you gain levels you get points to raise the skills you choose. Most skill increases result in accuracy/damage bonuses, but they can also unlock new abilities or extra power/skill bars. I hope that makes sense, it's not nearly as complicated as my description makes it out to sound. To compare, it works quite similarly to Fallout.
Most relevantly to the Codex, there are two dialog skills: Charm and Intimidate. They do what you expect. If your skill isn't high enough, the dialog option appears unusable in grey.
I probably spent as much time in the in-game knowledge base as I did actually playing the game. When people mention new topics in conversation, or you stumble upon them in the course of gameplay, the entries are added to your codex. There are also some "hidden" entries, in that you have to explore your surroundings. Click on the ship's engine, for example, and you get an entry about how it works (and +10 experience).
As for downsides, I haven't really been playing long enough to notice anything major. The texture-loading delays that people have been complaining about hasn't been very noticeable -- only when you load a saved game, and then only for 5-10 seconds.
At any rate, I should be out of the prologue soon, which I assume means that I'll be taking control of my ship, and I'll finally be getting to the real meat of the game. I'll report back later, if nobody beats me to it.
I don't think I ever saw the become a mutant bit for FO2. How do you get to that? It's probably just been too long since I last played it to remember all the details.
