Haven't played yet, but I like how it seems that most enemies are "deadly" and you have to be on your guard.
Not really. GROUPS of enemies can be deadly. If there's a special/tougher zombie in a group of regular zombies, draw the regular ones out first, kill them and then finish off the tough one when you can focus on it. I'm playing with a second player though, I could see this game being tough on single player, especially the few escort missions later on. Do all the side missions as you go along and level up, get better weapons and mods and you're good to go. I've found that in this game, electricity is your friend. ;)
Anyway, after the day one issues, we've had NO problems on the 360 version at all since aside from when my 360 locked up once, but I've had that happen in other games. It truly is an awesome experience... one of the best I've had for the current gen in fact. I've heard rumors the 360 patch might come out tomorrow... I hope not because we're 85% done and I know those patches really mess with in-game progress. I'd hate to lose anything like the PS3 people did with their patch.