"Must be really good I don't use a Mac though" is regrettably ambiguous. It can either mean "Dash looks great; too bad I can't use it since I don't have a Mac"

"Must be really good I don't use a Mac though" is regrettably ambiguous. It can either mean "Dash looks great; too bad I can't use it since I don't have a Mac" or it can mean "It's really great that I don't use a Mac", especially when read quickly. Also, you were terse so that there isn't much content in your comment. As always, ask yourself if your comment is worth the time for people to read. Cheers.