Put another way, comparing a 4x5" press camera to a 2x3" press camera in general, I find that my Linhof Tech V 23 kit takes up about half the space as my Linhof Tech V 4x5" kit with about the same number of lenses and other stuff, and I can use a smaller tripod with the smaller camera.
I agree. The camera is quite a lot smaller than the 4x5 model. Rather cute suckers, really...and very inexpensive for what they can do. I wish that there was a Super Speed Graphic version of them.
They are shaped differently than most cameras, so it is hard to make a comparison, but they are definitely very lightweight, and many times more convenient than the 4x5s, for the reasons David A. Goldfarb mentioned.
It is not the weight, but the available light and film used that determine whether on not you can hand hold.
I find that using the solenoid tripped from the flash handle (no reflector required) and left hand focusing makes a 4x5 Graphic much easier and more steady to handle than using the body shutter release. I always release the shutter this way, even on a tripod. Having the big handle is a great benefit. I do not know if you can squeeze a solenoid onto a 2x3 board. You can run a cable release from the body release up to the flash handle, and tape it on, however.