I've only used Garage Band on an iPad and found it extremely rudimentary. Easy to use? Absolutely, but that version felt extremely limited. On a full blown Mac system may be a completely different story, so I'll have to defer to others who've used it on that platform.
I also won't lie about the learning curve for Reaper. For me, coming from so many other DAW applications, I had both an advantage, and a disadvantage. I understood basic functionality and flows for most of them, so it wasn't terribly difficult to look for similar functionality and create a custom key mapping for my favorite functions. On the flip side, Reaper includes *so* many options to customize, it felt a little daunting. That said, for someone just coming into Reaper and learning it from the ground up from the get-go without having too much experience with a myriad of other DAW's might find it far easier to get up and running after watching a few videos. There are a TON of instructional videos out there for Reaper. My favorite being Kenny Gioia's "Reaper Mania" on YouTube. HUGE asset for learning the in's-and-out's of Reaper.
Whichever way you decide to go you'll be more knowledgeable, and have a broader range of experience to apply to future DAW choices. You really can't go wrong.
Good luck!
