Downsides of using Appcelerator Titanium (or equivalent)?

Question

At our company there is a huge push for cross-platform (iOS and Android) development. Appcelerator Titanium is being considered (and seems to be the only thing that's being considered) to achieve multi-platform development without extra development time.

Everyone here can think of reasons to use Titanium. For reasons against using Titanium I guess the performance of the resulting "native" app from Titanium may not be as good as an app written in Objective-C for iOS. How significant would the difference be? Are there other reasons to not use Titanium (or equivalent)?

Note: I may write Titanium but reasons may not only be Titanium specific only. All reasons in support for coding in platform language (e.g. Objective-C, Java) qualify.

Answer 1

The Good:

• Can create iPhone apps using very simple Javascript.

The Bad:

• Apple has been rejecting some Titanium apps due to private API calls but Appcelerator hasn't responded to requests for help, nor updated their SDK. http://developer.appcelerator.com/question/123785/app-has-bee-rejected-by-non-public-api

• "Native Widgets" are used, but only nominally: there's a layer of logic and abstraction between them and your code; and this layer changes their behavior and reduces their speed. The difference is visible in the Showcase apps.

• API docs are perpetually out of date. (no process for refreshing).

• A wiki was created, which is becoming out of date. Editing only
  allowed for employees.

• Github projects do not have wiki enabled.

• Appcelerator isn't true open source: they do not accept contributions from the community: The titanium_mobile project on github has a long list of open pull requests.

• The help forum software has many technical & design weaknesses.

• Email notifications from the help forum often do not work.

• Staff rarely answers questions in the Q&A forum. Haven't been seen
  in months.

• Showstoppers appear continuously in "all the little gaps":

• Correctly displaying images on the iPhone 4

• Correctly loading images in a scrolling list

• Although the platform does simultaneously support iOS and android,
  the library/framework does not. A lot of runtime testing (if/then's) is needed in apps that will work on android and iphone.

• Continually releasing new products but not fixing existing products
  and website problems. The "new" products are announced while in beta and release candidate phases.

• "Chat with Sales" app not attended to.

• Appcelerator does not take down outdated training videos.

• Stretching the truth and bait-and-switch with pricing: a 30% sale
  only applies to yearly memberships, not month-to-month. The blog
  posts & marketing materials do not state this. Only upon checkout is this shown.

• [Seen 8/13/2011] Another way in which Q&A forums are broken: The order of
  results for a search is trashed: each page of results orders its hits from oldest to most recent, at the bottom of the page. Go to the next page of results (i.e. 51-100), and again, the 1-year-old hits are
  first, with 6-weeks-old at the bottom.

My Unanswered Questions:

[Seven unanswered Q&A questions not shown: I don't want to be personally identified by Appcelerator staff and receive sub-par treatment.]

Results:

Am spending many hours trying to discover an API in the absence of documentation, and hacking to discover workarounds. This time is wasted, and would have been better spent simply learning to make apps in XCode & Objective-C.