If a client requests a Digital Betacam I would usually rent a DVW790(ws) The DVW700WS is an older model. My only beef about the Digital Betacams is that are they are heavy and power hungry. I get maybe 4 or 5 jobs a year that would require this camera, otherwise its D600 or 400a.
I'm using the Varicam HD27F today on a shoot.
A really nice camera to work with, awesome viewfinder. Feels more like a Betacam than a HDCam does. The menu is easier to use. 24P looks great.