Can anyone tell me advantage or disadvantage of using one over the other?

My scenario is that I am writing a C# dll for an external .Net application  I am writing.   Currently I started out using Accpac.Advantage but am unsure if that is the best approach.   One issue I am having with that DLL is that there does   not appear to be any .Close() methods for the session or dbLink.   I undertand the Comapi may offer that.    Or another approach is - is it possible to access the COMAPI connection to close is and still use .Advantage objects as well?  I am to understand that if you don't close the session and link, bad things can happen.