So, here there are some of the cases, what I think about their functionality and if they really work well for the daily needs.
Open cases
Advantages:
- almost full protection when not using it
- friendly ports when using it
- not bulky, so gets its beautiful shape
- easy slip
- prevents from scratches over surfaces
Disadvantages:
- no protection when using it
- no protection on the top of it when it's not in use
- only can used one of the ports when it's inside the case
(or listening to music, or charging)
Conclusion: Recommended
*****
Semi-open cases
Advantages:
- almost full protection when not using it
- friendly ports when using it
(with Bumper only can be used the Apple plug to charge)
- not very bulky
- pretty easy slip
- prevents scratches over surfaces because of the 2mm case
Disadvantages:
- no back nor front fully protection
- some people has realised that it scratches a bit of the aluminium
(in my case it have not)
Conclusion: Recommended
*****
Close cases
Advantages:
- back protection
- friendly ports (headphones minijack, 30-pin dock connector, mic)
- some are not bulky (thick plastic)
- easy slip
- transparent
Disadvantages:
- when making a picture with flash it gets blur and upper lighted
(very bad!)
- non aluminum protection
- some are made of rubber, so it gets difficult to get out of pockets
- some are made of very robust material, it makes it bulky
Conclusion: Not quite recommended
*****
Other protections
Advantages:
- full screen protection from scratches
Disadvantages:
- some of them get finger prints which original screen does not
Conclusion: Very recommended
*****