I spent four years developing Ruby full time. The last few years, I've been doing iOS full time, and there's no way I'd add a third-party layer to my app.
If you want to ship a high quality iOS app, you need to understand Objective-C inside and out. If you are using RubyMotion to avoid learning Objective-C, you will ship at the the cost of massive technical debt.
If you already know Objective-C, Ruby gives you a more concise syntax. Having used both languages for a while, and now that ARC exists, I'm comfortable using Objective-C as a high level language. Objective-C is wordier than Ruby, but when I return to the code a year later, I can still understand what it does.
As much as I hate Xcode, Apple expects you are using it. Sometimes features land in Xcode a version ahead of the command line tools.
For the handful of benefits I see from RubyMotion, I see a mountain of risks. Will Apple change its policy on accepted languages? Will the translation layer blowing up when you need to ship a hot fix the day before the iTunes store shuts down for Christmas? Will someone acquire the RubyMotion team and sunset the product?
Maybe I'm a different target audience. If an industry-changing platform appeared, I wouldn't leverage what I already know to dabble in it. I would do things the idiomatic way. Even if it takes longer to ship my first app, I think it's the faster path to mastery.
If you spent a few minutes to read RM's doc you'd have seen that RubyMotion runs on top of the Objective-C runtime. The only thing it "replaces" is the language, the syntax if you will. API, calls, parameters, ... all is native. This is not Adobe Air, it's Ruby on top of the Objective-C runtime. There's no translation involved, no interpretation.
If you want to ship a high quality iOS app, you need to understand Objective-C inside and out. If you are using RubyMotion to avoid learning Objective-C, you will ship at the the cost of massive technical debt.
If you already know Objective-C, Ruby gives you a more concise syntax. Having used both languages for a while, and now that ARC exists, I'm comfortable using Objective-C as a high level language. Objective-C is wordier than Ruby, but when I return to the code a year later, I can still understand what it does.
As much as I hate Xcode, Apple expects you are using it. Sometimes features land in Xcode a version ahead of the command line tools.
For the handful of benefits I see from RubyMotion, I see a mountain of risks. Will Apple change its policy on accepted languages? Will the translation layer blowing up when you need to ship a hot fix the day before the iTunes store shuts down for Christmas? Will someone acquire the RubyMotion team and sunset the product?
Maybe I'm a different target audience. If an industry-changing platform appeared, I wouldn't leverage what I already know to dabble in it. I would do things the idiomatic way. Even if it takes longer to ship my first app, I think it's the faster path to mastery.