Honestly once you are set up initially in MYOB, if you enter your transactions regularly (which isnt much more difficult than entering them into an excel spreadsheet), running your reports and filling out your BAS takes a matter of minutes.

I take a bit longer than a few minutes at BAS time (but not much) simply because I like to double check stuff and make sure it all looks intuitively correct.

As I said before you can make MYOB as simple or elaborate as you need. You can run most transactions through only a handful of accounts or make it as detailed as you want, using lots of accounts and card files etc etc if you feel that helps or your business really needs to break stuff up a lot more for say analysis and planning.