45mm f2.8 macro experiences?

I'm despairing of Lumix bringing out a short telephoto (45mm 1.7 would be nice) so I'm seeing if I can pick up a 45mm macro used. However I can't even find a new one to try out, other than online they're that rare!

Does anyone have one? How are they on focusing? I find the 14-45 is much quicker (and transparent) compared to the 20mm pancake - I wondered if anyone could pop in a comparison of the 45mm?

And since I'm trying to achieve a shallow depth of field, any comments on their performance wide open?