Well I was going to ask you how much you like to customize, but you really wouldn't know yet still being a BB user. I came from a BB Curve last summer and bought a Moto since the original Droid had such a successful following. But when I bought it I didn't know what a bootloader was, let alone what locking one meant. Now I know, and I must say with my desired level of customization I wouldn't have bought it if I knew then what I know now.
Not that I don't love my X, and the locked bootloader certainly doesn't make it worthless. But I would have been much better off with an unlocked bootloader. The real problem is that there isn't a device on the market that fits all of my criteria. I really like the durability of the Gorilla Glass screens Moto uses. But I like the customization level of HTC devices and their easily pickable bootloader locks (ok, basically the locked bootloader keeps devs from being able to replace the kernel. Which means when they have to work around it when creating custom ROMs.... I realize thats all Greek to you, but once you get into custom ROMs you'll figure it all out).
So my dream device has a 4.3 inch screen cut from Gorilla Glass, easily customizable (think Nexus), with the most advanced processors and graphics chip sets available.... with a gig of RAM to boot!
So I guess between those two I'd proly have to go Thunderbolt. Not that I want a 4g device yet, I'm not in an area that supports it.