I use iReal on MacOS too. I have used BIAB for over twenty years and I love the program. But between having to pay so much for upgrades each year to stay current on new versions of MacOS, and the long delay in BIAB working well on new operating systems I am seriously considering removing it and going with iReal. BIAB is a far superior product, but I just use it for play along to practise improvising, not performances or recording, so I could live with the more restrictive combos and patterns on iReal. Staying with BIAB means I pay a lot of money every year for functions that I don't really use. I dread to think how much I have paid over the years. Thousands of dollars, I suspect.