I have experimented with it. I replaced the supplied sizing with shellac. Then fine sanded that to smooth down the raised wood fibers. Also thinned down the glue to get a smoother coating. That worked better for me, but the unsteadiness of my hands wasn't so easily overcome. I decided that the antique look, where some of the leaf appears to have rubbed off, was my preferred style... : ~}
e.g. this one sold at the gallery last week. The photo doesn't quite pick up the true colour of the gold, which is 23K leaf.
Yes, a bit fiddly to apply and to do well. I'm also yet to be convinced that you can get a sufficient return at the gallery for the extra cost and effort involved in using gold leaf. Perhaps better reserved for exhibition or other special purpose pieces where those inputs are of a less consideration.