So after 5 weeks of having the casemate jett case fitted I can update my thread with confidence.
No marks or scratches on the outer case.
No finish wearing off.
No loss of network signal.
No loss of 3G or wifi signal.
No scratches to the iPhone's steel antenna band.
The metal buttons give great feedback when used and do feel as they are the the originals.
No failure if the two plastic bungs in the case where the natural breaks are on the iPhone 4 steel antenna.
The only issues I can see are ;
If your using a 3rd party dock then their may be an issue due to the recess the case gives on the 30 pin connector port.
The case gives the phone little grip in the hand. Just like it's naked still !
The recess created above the headphone jack may cause some issues for users with L shaped jacks.
I use monster turbines which are fine as they have a straight jack.
Make sure it's fitted at the top first or the plastic inner concealed hinge can fail as it's forced to close in the wrong way.
The black colour of the casemate jett is not available thro amazon uk so I had to order from amazon us from casemate which was more expensive and I had to pay a import duty of another £14.00 sterling ontop when I collected it.
My conclusion is that if all the different metal style bumpers the casemate jett offered me what I wanted. A metal bumper that didn't degrade signal , have a big plastic insert where the antenna break is and was truly fully enclosed around the phone as some have just cut outs where the phones buttons are creating a dust trap.
If you need to take the case off to use a 3rd party dock then your gonna need to carry a small screwdriver around.