The pros are that if you have multiple systems the management is all done from one location , (that said manager now has the scn feature to manage multiple kits) , the cons in my opinion are that SM is a total pain in the ass for configuring systems due to the fact i simply dont like the layout , there are no help files or guidance relating to the kit you are programming that is of any worth , its obviously web based and is syncing live as you do the change so unlike manager when you commit you commit so no sanity check.
In my opinion SM is a nice tool for its initial purpose and that's configuring session manager and SIP endpoints , for configuration of systems use the tool that was designed specifically for the purpose , its a familiar interface that works correctly and allows full control , SM for example cant do half of the things on a IPO that manager can do ..... just stay with what you have or you will end up wasting time and effort
APSS (SME)
ACSS (SME)
ACIS (UC)