On-screen keyboard vs. hardware QWERTY keyboards

I've had the opportunity to use a variety of different smartphones. Some have physical QWERTY keyboard buttons. Others are slates that only have an on-screen keyboard. As I've compared different QWERTY keyboards, I've found that some smartphones (like the Palm Pre) have tiny buttons that are literally impossible to push unless you have small hands. Others (like the Motorola Droid) do not provide enough tactile responsiveness. This has been changed in the Droid 2 - which has a much better keyboard compared to the original Droid.

My favorite QWERTY keyboard was the one found on the HTC Touch Pro2.

Now that I'm mainly using the Motorola Droid X which lacks a physical QWERTY keyboard, I'm finding that the large 4.3" screen provides plenty of room for a great on-screen keyboard that is very easy to use when I hold the device horizontally and type using two thumbs. The Droid X also provides the option to use Swype so that you don't have to lift your fingers or thumbs off the screen as you enter text. Which input method do you prefer?