I've used a fair share of metal bumpers in the past with my iPhone 4 including the Blade, Deff Cleave and now a Vapor Pro.
Short summary on the cases:
Tiger Design Blade - Very attractive looking case. But I wouldn't quite recommend this due to the fact the supplied buttons are all metal and there is no form of cushioning beneath them. This causes the buttons to discolour your volume and power button after prolonged use (I used it for about 3 months). Your chrome volume buttons and power button will then be a faded and dark chrome. Also the dock cut out is extremely small. No third party docks will ever work with this case unless they are only as big as your normal USB charger. Edges are sharp as well and if you're not careful you could hurt yourself. Takes some getting used to.
Deff Cleave - Very nice case with not very rough edges but again, dock cut out is so small that you can't fit anything other than your iPhone USB charger. The supplied volume buttons are metal as well with no cushioning so you might get the same problem as the Blade. Buttons does not snugly fit into the holes as well. When you shake the case you can hear a very very annoying rattling of the buttons. This can be solved by pasting some tape on the buttons though.
Vapor Pro - What can I say? The perfect case. IMO you don't have to buy the original. I've seen some sellers selling really high quality fakes and they work just as well as the original. The cut outs, the feel, everything is just perfect. Not that I am advocating piracy here (I'm using an original myself) but I do understand its very expensive and not everyone can afford it.
Conclusion - I've never experienced any signal issues with either case. If you are in it purely for looks the Blade and Cleave are very very nice looking cases but fall way short in terms of functionality. If you are more of a functionality person with third party docks and earphones, stay away from the Blade and Cleave.
Added on December 4, 2011, 1:10 pmQUOTE(Mini Nici @ Dec 4 2011, 11:51 AM)
Look at the design which comprises of top and bottom pieces with screw tightening at 4 corners. I doubt the tearing of SP is due to the case itself.

Added on December 4, 2011, 11:53 amYeah kind of love red white combination. I wonder whether there will be graphite like vapor.
Looks nice but I'd stay away looking at that design wise. Again poor cutouts which will cause incompatibility with third party docks or earphones/headphones. Volume rocker and power button are metal with no rubber/tape below it. It will discolour or cause your volume buttons and power buttons to fade. Solution is you can add tape beneath those buttons but it will cause your buttons to be less sensitive.
This post has been edited by sigheart: Dec 4 2011, 01:10 PM