The first one:
Pros:
- Easy to navigate
- All cities are visible without too much scrolling
- Selection is extremely easy - anyone can do it
- De-selection is extremely easy - anyone can do it without instructions
Cons:
- Lots of information may be too much for the average user
Second One:
Pros:
- Allows for selection viewing
Cons:
- May require use of ctrl and shift keys (multi select) to select item
- How selection moves from left side ctrl to right will define how difficult it is to navigate (in other words, does dbl clicking remove it from the left list, or just place it in the right... Very confusing if the latter)
- Then what if the user wants to remove a selection from the right side. Dbl click again?
- Requires instructions on how to use control
The point I am trying to make:
Top easy for everyone, bottom more difficult for a novice user.
Hope that helps.