Eh, this game it more like a Fallout Total Conversion of Oblivion, rather than a different game. Although the benefit is that since Oblivion was running on an FPS engine, at least the combat isn't as horrible (They should have made a proper melee engine, rather than tacking weapons onto an FPS).
The repair system is horrible. I get my repair skill up to 100 only to find that the only way to repair the things that I have is to find another of the same item. This completely ruins all quest items, and having the best armours, because you only can use them until the break, or find someone who you want to pay to fix them to a third of their full integrity.
I thought the game was good, but not great. It falls victim to one of the issues Oblivion had, which was you'd get a few great quests, then a fetch quest that would take forever because of the size of the map.
And I wish the saying "Great Games sell, crappy ones don't" was true. But it's not. You can find lists of great games that the general public ignored, that many would agree were great. And look at a game like Carnival Games which sold over 2 million copies.
Hype sells games, not quality. Fallout 3 has been a big deal for a while, so it's not surprising that it's sold well. What really cuts down on piracy is price. When I can buy 5 games for $100, why would I go through the hassle of waiting days to torrent, and get cracks working? When I can't even get 2 games for $100 I'm more inclined to.