No idea what MYOB is but I have been using Quickbooks for seven years in my business. It's very straightforward to use, processes VAT at a stroke, gives customised invoice templates, memorised transactions for repetitive items & also allows you to go back and void or delete mistakes as necessary - hence the nick name cookbooks.
I looked at Sage but decided against it as at the time, the modular design made it expensive. £99 for sage instant accounts but by the time one had added vat, invoicing etc it looked more like £1000. Whether that's changed or not I don't know.
At the very beginning, I had Omni accounts which was awkward to use. I had a problem & opened a ticket. This was in 2004. They emailed me last week asking whether or not I had resolved the issue!! Is this a new record? Even AOL aren't four years bad!!