Okay, here's the deal. Read quick in case they decide to delete this.
The iPhone 4 is the best smartphone I've ever owned, and I've owned plenty. This was an upgrade from a 3GS, so I've been in the iPhone camp for awhile.
It has also been the most frustrating thing I've owned in awhile. Yes, the antenna issue is real. No, a case will not solve the issue 100%. Yes, when you're in a good signal area your signal doesn't seem to drop. No, I'm not in one of those areas most of the time. Yes, the screen is amazing. No, mine doesn't have yellow spots, nor has it ever.
When it works, it's wonderful. It is the first phone I've been able to take three stories underground inside a server lab AND still make calls, as long as I don't touch that little band.
No, you don't have to squeeze the living **** out of it to make it fail. "Death Grip" was spin designed to try and put the blame on the user, when all you have to do is lay a finger on that spot to cause it to fail.
A fix will come and when it does the phone will be amazing consistently.
For me, needing the iPhone and the apps available, the hassle of remembering to not touch the left corner is an inconvenience, and it IS a functional issue which should be addressed, but even with this issue, the phone still beats anything else I have available to me.
My company is an all iPhone shop, so I need one too; and although I COULD go back to my 3GS, after using the 4, that just isn't going to happen.
So I use my case, try to be careful when talking and eagerly await a real fix, because "hold it different" is not an answer I will accept.
Get the phone. You won't be sorry.