I still use Crew Alert Pro, and used to mix it up with a Readiband (SAFTE) last year.
On the whole I found Crew Alert to be more forgiving, ie less critical, than Readiband: it would allow flights that the Readiband didn't, but I don't think that was your original question.
I keep everything in my local home base time, with "Acclimatization" set to off. Just need to make sure I log everything in the correct time zone!
My employer uses both: SAFTE-FAST in the Safety Department, and BAM by the rostering department. It's very hard, if not impossible, to accurately compare different measures of fatigue/alertness/sleepiness across different mathematical models. Having said that, one can directly read (via interpolation) the CAS score into a Samn Perelli and Karolinska Sleep Scale, but not so easy to compare with SAFTE. I use 75 (SAFTE, about 0.06% BAC) as roughly equivalent to 1700 in CAS.