If we’re talking about the iBooks publishing app, yeah, I’ve heard of it, but have also read some disturbing things about the limitations its present ToS puts on the books you publish with it: see here. I wouldn’t normally allow a publisher to slap such a restriction on my work.

I might at some later date try this on just one book and see how it performs compared to others published across other platforms. But at the moment, the very thought of the restriction irks me. I’d sooner do my production / conversion in Calibre and handle distribution separately and on my own terms: if Apple wants my stuff they can work from my ePubs.

Meanwhile, you don’t need an app to find out if anyone’s interested in your work. With your present equipment, just use Calibre or a similar free tool (Smashwords has a converter built in), publish the stuff, and see what happens. If you have some success, you can always consider going up to the Mac later.