It is worth considering who benefits from a unit power finder. The accuracy of such a device is on the order of 1/4 degree, and thus is perfect for the observer who can see a naked-eye target and wants to align on it. These days, one quickly recognizes that such a device is more than adequate for the user who simply wants to complete a quick two-star alignment on his or her DSCs. You will not be happy with such a finder if your goal is to hop from 7th magnitude star to 7th magnitude star across 20 degrees of sky to an NGC object to be named later. Such activity is best left to users of a magnified finder (which allows for sighting of fainter stars), or to the Telrad, with its 1/2, 2 and 4 degree circles and a cult following of aftermarket, Telrad-specific finder charts and software. For the obvious reasons, this sort of finder is inappropriate and unsafe for solar use. Unit power finders do not have the pointing accuracy for locating an object at high powers. It is necessary to acquire the object at a lower power, then move up. I have had consistent success with locating an object at up to 125X.
The only real advantage of this finder is aesthetic. Personally, I cant imagine taping a Rigel Quick Finder onto my NP-127 or DM-6. I have known others who did so, and with good results. I use a QP on my sons small dob, and I have used a Telrad on a larger dob. I have been happy with their performance. The SV is not a small finder, but neither does it stick out like a sore plastic thumb on my refractors. It looks like it belongs with the equipment. This may be vanity, but my WO lives in the living room, and the NP127 lives in the family room, in both cases with the consent of my wife. I find the pointing accuracy of the SV more than adequate for my two observing patterns--DSC driven with the NP127/DM-6 and quick, generally rich-field look with the WO 80mm. If the appearance of a plastic finder on your scope does not bother you, save your money.