The reason there is no problem with the iphone 4 antenna is not that it is impossible to obscure the signal or cause signal loss, but because the new design pulls in signals better-- over all-- than the previous design. The issues you can cause it to have exist on other phones as well.
It is a better design than previous versions, yet people seem to think there is a defect that makes it worse.
I don't doubt there may be better phones out there, and as you note the results will vary by location, and I'd add, carrier.
The antenna apparently has more gain, but the design flaw was that its conducting parts were on the outside of the case. That's just asking for trouble in a hand-held device.
But they are apparently on top of it. As soon as the flurry of complaints came in, they posted a job opening for an antenna engineer!
It is a better design than previous versions, yet people seem to think there is a defect that makes it worse.
I don't doubt there may be better phones out there, and as you note the results will vary by location, and I'd add, carrier.