I personally haven't used one before, but the main difference your going to find between these and the HMC/HPX/HVX's is the chip set, this camera uses smaller chips I think 1/4 chips where as the standard 3CCD HMC/HPX/HVX's use 1/3, just means they're usually better for getting colour and image quality.
The plus side of the camera you're looking at here is that its SD card as opposed to the P2 cards the HPX & HVX use, makes it easier for you to get storage.
The HMC40 is like the semi, semi-pro camera... it'll be good to learn on but if the end game is to film more, you're going to end up upgrading later after you realise the limitations on this cameras options and settings.
I'd suggest saving up for a HPX or HMC if you can