Whoa, I have no idea where you are hearing that. If you are getting in to rooting, I would give the advantage to Samsung. The new EVO has a locked bootloader, which must be unlocked in order to root or flash custom software. As I understand it, you can re-lock it, but they can still see that it was previously unlocked and that voids your warranty.
Samsung, on the other hand, does not lock the bootloader. In addition, Samsung also has the Odin tool that can be used to make firmware changes to the device via a PC. This tool can be incredibly valuable allowing you to recover a bricked phone. As far as I know, there is nothing like this available for HTC devices.
I have rooted previous galaxy devices, and the process is very easy.
