I’m only linking to this review of the HTC Thunderbolt because it reinforces my existing views:
Then I could go on to say it doesn’t have an antenna issue like
the iPhone 4. That would be a lie, because it does. If you hold it
wrong then you’ll be constantly losing your signal and wonder
why. I emailed HTC’s support team about this and told them that
it really needs to be fixed. The man told me “Hold it
differently.” It seems that any way I hold it causes a problem
with the signal, no matter if it’s on 4G or not.