I wanted to post a similar review in these days. Beside all the positive aspects you mentioned I find it also quite annoying that display.newText() y-position is always different. It's too low on iOS devices and somewhere in between the simulator and iOS devices on Android.
Having no dynamic Scrollview Masks is very frustrating especially in the year 2013. I have to say it quite frankly, Corona spent about half a year rewriting the whole widget library without many obvious improvements ( yet ) plus the community spending their time sending bug reports, etc....
I know they did it because they built it from the ground up in order to make it more flexible for future-improvements.
And as Brent mentioned it will become much better in the near future. Hopefully we'll see this improvements very soon.
I don't really understand why Corona as a company don't hire more people, make the company bigger and spend more time in developing new features. Especially when it comes to audio, bitmap manipulation, including third party librarys and some other general features... I mean, there are new features coming but compared to other third party kits it takes way to long..
On the other hand it has many advantages. I like how the API itself is built up. It's very easy to do graphics stuff, I think Corona is ideal for Games. And when the code works it seems to be very stable, compared to other third party kits Corona is very fast and solid indeed. Maybe it's good to mention that I currently use it for a big buisiness app and therefore have another perspective on this.
I also like the community a lot btw
So big credits to Corona and everyone else here. But there's still some stuff to do.
And good luck with your game, haven't tried it yet but the screenshots look amazing