Customers most agreed on the following attributes:
Works as stated. Great solution for those without the money to buy a macro lens. One slight problem is the reduction of focal length. (With the +4 you have to get nearly 2 inches away from the subject.) However, this is to be expected.
Inexpensive and practical way to enjoy close up photography.
Bought this set to use with my Nikon 35mm f2.0. Gives good choices between close focus and working distance. Not as close or sharp as my 10x diopter, but even the 4x gives much better working distance and DOF. 4x is very sharp at f11 and above but still allows good working distance from subject compared to 10x, which won't focus past about 6".
I own 3 lenses (2 canons and 1 promaster, 52mm) none of my lenses could focus with these filters attached.