I own the MH-1301 with Arca-Swiss style QR and have often thought that the screw-on version might be lighter and more handy in many situations. It is also $45 less expensive. I have used the screw-on type platform with a ball head before and they work pretty slick. Just release the ball, cant the head over to the vertical position, grasp the camera firmly, and rotate the platform to unscrew. Another plus is that you can mount multiple bodies without having to buy a bunch of plates ($10 - $30+ each).
As far as advantages to the QR type, consider my shooting scenario from a few days ago...
I was in a local demonstration garden doing some test shots with both a Helios 44M 58/2 and Jupiter-9 85/2. I was moving from subject to subject as well as changing off the lenses frequently. The QR allowed me to remove the camera easily when adjusting the tripod height as well as for when I needed to change lenses (a real pain with the M42 screw mount). The screw-on platform would have worked, but it is just a little more time consuming.
It might be good to note that the platforms are user-changeable. If you decide to get the QR platform, you can do so at a later date for about $60.
http://www.bhphotovideo.com/c/product/490030-REG/Giottos_MH656_MH_656_Quick_..._Assembly.html
Steve
(BTW...the MH-1301 is a great value in a ball head...Ditto for the Slik Pro 700 DX legs)