Will this work on the XH-A1?

Century Precision Optics AD-7220 +2.0 Achromatic Diopter

http://www.bhphotovideo.com/c/product/77528-REG/Century_Precision_Optics_AD7220_AD_7220_2_0_Achromatic_Diopter.html

It would be a good high quality macro solution right?

I'm also interested in macroshooting with the XH-A1...
Are there any important downsides of using devices such as the one Brett mentioned???

You should test the specific adapter you have in mind in the focal range and subject distances you are planning to use. Some may exhibit unacceptable image distortion if used outside their intended range.

Anybody? Anyone used this? This is a pretty big basic question - how can we shoot macro on the A1

Century Optics achromats are top notch. I use 7235 which has 3.5 magnification and I love the results. I bet 7220 is great also, just with less magnification.

Attached is a quick handheld example taken in Photo Mode. In this case focus was set on the center of the coin, but if you're after corner to corner sharpness in flat images, it will be very good with those diopters.

Bogdan: Nice photo. What zoom setting did you use for the photo of the coin, or alternatively what was the distance from lens to the coin?

In this case I was close, about 1.5" away with zoom set 55 or so, but of course other distance/zoom settings are possible as long as lens can achieve focus.