My own personal experience flashing just about every ROM for the V and having used 4-5 different recovery's. Absolutely does a better job. I don't have any of the problems associated with leaving residual data when I use it.
It also allows me to use ROM Manger to install a Froyo, CM-7 or CM-9 ROM. With it I can do everything without having to boot into recovery, do all the wiping and formatting and then have to wait for the install of the ROM and then wait for the install of the gapps, and reboot into system.
I do everything from the ROM Manager screen it takes care of everything else including booting back into the new system. I use it when I don't have the time to come back and wait to do the next step, and wait to do the next step, etc. One time, set the phone down , come back to a new ROM installed.
Without that wiper.zip It is impossible for ROM Manager to wipe and format everything necessary to install a CM-7 and CM-9 ROM and the ROM's will become corrupt from the residual data.