Z-Communication VCOs [question]

hello
I have a question:
Are Z-Comm VCOs good choices for designing PLL frequency synthesizers? Please write about your own experiences also.

Their VCO's are of good quality and performance. I have used them before in several products in the 1-2GHz range. They used to be much better (low PN) than the Minicircuits stuff although I have not compared them lately.