It does have a few perceived shortcomings.
1) Very heavy on the graphic resources: This often leads to improper shut downs of the program, visual errors and memory issues. This has some to do with our choices in hardware, but it is very resource intensive.
2) Pre-auth: Some programs will allow your pre-auth to be adjusted in the upward direction. Acctivate is not one of those. You must delete it and then charge separately (effectively removing double funding from your customer).
3) Sensitive order of operations: There are some actions that must be done in order. If you don't, you end up in an endless error loop that could eat of 5 minutes of your time. For example, if you have a dropship D and a lot number assigned. If you change it to a Stock Shipment (P) before removing the lot number, you will end up in an error loop.
4) Windows: You are only able to have a finite (20's ish for me) amount of windows open. Furthermore, the window button only shows you 10 active windows. So if you are using 15, you can't switch directly to them using the window tab.
There are some more that could eventually be improved upon, but these aren't "deal breakers" just improvement possibilities. Review collected by and hosted on G2.com.