Unfortunately, all those tech and biotic power animations flying around can cause the frame rate to suffer on less than godly computers. This will really only happen during battles with numerous foes, and though it isn't much more than a brief stumble, it's distracting. Slightly more distracting are the frequent in-game load screens. Masked by long elevator rides on the 360, load times have actually decreased in length but increased in frequency for the PC version. Elevator rides are shorter, but you'll often be ambushed by a two- to four-second pause (the screen dims and a small "loading" icon appears) when you're coming up on a battle or entering a new area. Again, these pauses are brief enough that they don't bring things to a screeching halt, but they are a bit of a nuisance.
A few other tweaks have positive effects on the game. The inventory system is much easier to manage with a mouse and keyboard, and long lists of items won't reset to the top every time you sell something near the bottom. The Mako vehicle sequences are easier to manage thanks to the implementation of dedicated forward and reverse buttons in place of the 360 version's viewpoint-dependent controls. A new hacking and decrypting minigame, in place of the old button-matching one, is both more interesting and more suited to the game: You must move a small arrow through concentric circles to reach the core while avoiding stationary and rotating barriers. It's generally easy to accomplish once you get the hang of it, but the time limit and tricky perspective shifting help keep it entertaining. Keyboard hotkeys allow quick access to the map and squad upgrade screens, and the quicksave button is a great way to ensure you won't have to do too much backtracking. They aren't big changes, but the aggregate benefit is definitely noticeable.
All the things that made Mass Effect great on the 360--the story, the conversations, the galaxy, the combat, the soundtrack, and the characters--are still great on the PC. The changes that have been implemented don't radically alter the game in any way, but they have enough of a positive impact to make it easy to recommend the PC version over the 360 version. On top of that, BioWare is offering the downloadable expansion "Bring Down the Sky" free to PC players, though at the time of this review that content was not yet available. Whether you're a seasoned Spectre looking to suit up again, or a newcomer who has never set foot on the Normandy, the refined PC version is your best choice for experiencing this excellent game.