It's all about the niche in the market. I have found that most if not all companies with billing software design an excellent billing program and then as an afterthought, make a scheduler. For instance, it took me one day with eMedware to realize that scheduling lunch or putting in that someone would not be in counted as an appointmented. No shows count as appointments. How difficult would it have been to put in a little check box that removes that appointment from the total for the day.
I would rather spend more time on the scheduler than a PM. But, then that's just I. Many others would prefer a PM. But, either way, I would think Jon would need to do a lot of testing in order to put it out there as a full version.
And, I don't know how many times I have said this, but if the ICD-9 and CPT codes are already lacking in accuracy and functionality; and they are the cornerstone of practice management, it would be difficult to produce a good PM.