Mike, the trick with Zia's is the same as the Ware/Meade - the humidity in the paper. Not the humidity in the room, but the paper - it really makes a big difference in color, contrast etc. I found there were only certain conditions where I could count on a Zia coming out the way I wanted it to.
Curious why you mention the cost, as you can use the same metal salts so only the AFO vs FO would be different. I finally yielded and went to DOP vs POP just because it was easier in the end (yeah I know it was a co-out). I use LiPd for my DOP and get a totally different range of colors, than when using NaPd or KPd.
In the end, it is what you enjoy/prefer I found. Don't give up on the Zia's they just take a bit of getting used to - think most of best results were in the fall when it was not quite as hot and the humidity was around 60-70%. Still had to let the paper set out and reach the humidity of the room, etc. The big risk is not using a mylar sheet between the neg and the substrate, lost a couple of negatives that way...lesson learned.