SLIEB  I'm using PrintFab almost a year now and I had no problem purchasing it. Results are very good on my two printers (Epson Pro 3800 and HP B9180) - both fineart and prepress prints look very good. In my opinion, the workflow may not be 100% intuitive, but once you have found where the relevant settings are, it's quite simple to use. Technical support was excellent - the manufacturer responds to queries quickly, all updates were free so far. Good to hear that now it also supports SnowLeopard.  
(Version 2.14)

ARISTOPHANES  This is a much needed print profiler utility that, unfortunately, does not work very well. Printers listed on the website as supported are not listed as menu choices where necessary. It is hard to navigate. The process for profiling and colour management should follow the workflow, but it does not. I suspect the underlying code and framework is decent, but the UI and visible process is lacking. Hopefully this will improve. As one other poster noticed, for a demo, it's impossible to actually buy this product!  
(Version 2.09c)

NEALNT  These drivers seem to work very well. However I have not found a way to purchase the program as the site's purchase form does not work.  
(Version 2.04)