the new engine is i believe just that new, they've called it Creation. from what i've heard and read it is not a modification of the Gamebryo engine, and they game ive had the most bugs with was New Vegas which was developed by renowned buggy dev Obsidian. i didnt find many bugs in Oblivion some where present and really really annoying like the GOTY edition not being able to cure Vampirism at all. and with a game this size can we really expect perfection, really dev's cant really anticipate how the code will act together, two distinct lines might move a non essential npc of a cliff, and his only use being he has an item we need, there will be some bugs but Beth has Q&A unlike Obsidian so any massively game-breaking ones should have been found. unless the testers are very very very very poor at playing games.
a note on testing. even if say you or me found a bug, how many of us would be able to accurately describe the issue. sure we might say. i found a guy in a wall, but thats just the effect not the cause so then the dev would have to go through everything you did up to that point to find out why the guy is in the wall and that might not be the cause i might just be a glitch somewhere in the bowels of the code. fixing bugs is not a 5 minuet "bodge job" so anything that is wrong will be fixed eventually. and in the mean time the people of the internet will work out a way round and in this case a pc player can just use the console commands.
