- No Interface builder. Really a big loss given the power of Storyboards/segues, layout of objects, complex flows. - No syntax/error checking as you type -

- No Interface builder. Really a big loss given the power of Storyboards/segues, layout of objects, complex flows. - No syntax/error checking as you type - No static analyzer - No code completion (perhaps you could find a 3rd party module to do this eventually) - No refactoring support (very important in larger projects) - Probably longer compilations (in Xcode/ObjC the compiler will know which files are modified by looking at the included headers and only recompile what is needed, in Ruby I would expect it's gotta do them all but could be wrong).