I love that this is an all-inclusive service, so you don't have to worry about having too many different types of software - it's one place for your scheduling needs! My biggest issue with MSSP was when they first started charging monthly recurring fees after we switched our main office from using their free trial account (which offered unlimited users).
The benefit has been well worth paying $50/mo in addition each month since then though. There are no downsides as far my knowledge goes!! We use msps daily through out every department at work because there just isn’t anything better if looking specifically into payroll or timekeeping departments etc..