Had some serious issues with the first one when I rented it recently. The two biggest were the lack of storage (Something Borderlands needs to learn as well. You have a game filled with random and unique weapons. Take the bottom out of the fucking storage bins.) and the save system, which was just shit. (Borderlands also has this issue, but it's not nearly as bad.)
A third problem was the shitty, ghetto ass map the game had.
I can't believe companies are still fucking these basics up.
Must have's for any type of open world game:
1. Clearly defined spawn points (if you are not using a "continue from last save point" feature.)
2. Scrap #1 and let us save wherever the fuck we want.
3. Bottomless storage, and early.
4. Easy to read and navigate maps.
So that being said, they will have to show me some serious improvement if they want my money.