b+w diopter

Has anyone used the B+W brand ?
What would be best for 17-55 and 70-200 mk II - flowers and bugs ?

A diopter 'close up filter' is the wrong approach to take with any dSLR that has a removeable lens. Far better to use an extension tube, since no supplementary optics are employed.

A close up filter was designed primarily for cameras with fixed lenses, since there was no other way to accomplish closer focus. At the minimum, buy one of the Canon close up filters, which uses two elements in the filter, rather than the more simplistic single element close up filter.