I have been looking at appcelerator it seems pretty fine! Without a doubt, one of the advantages of appcelerator is its support for multi-platform. I am interested in building an android app and maybe a iphone app later on. So it is not crucial to support multiple platforms at the moment.
If you disregard supporting multiple platforms and just focus on android development. Is appcelerator still advantageous? Does it lack any features of "Android sdk"?
(When I say "Andorid sdk" I mean development with Eclipse with native Android sdk, if it makes any sense)
that is a very difficult question to answer without any specifics regarding the requirements of the application.
I would suggest you take a quick look at the API documentation of Appcelerator to see what the framework provides and also take a moment to list the basic requirements of your application and then determine what tool will be best for your project.
Well, in the new version of appcelerator (APPCELERATORSTUDIO 4.0) you can have alloy projects, and something like css files for your UI (tss), so in fact they are really customizable.
Greatings
Lacking of bluetooth support is a huge deficiency for Appcelerator and no one gives a clue about roadmap.
edit : appcelerator now have BT support in Tizen 3.1
Appcelerator has a lot of support and it really easy to use. It supports 100% of native api calls now. They have really good documentation too.
I think you are onto a good start using Appcelerator, since it uses JavaScript, etc. Easy to learn, but good examples. It will also enable you to use the same code and reach iPhone,iPad apps. Learning to use just the Android SDK is more complicated. Even then you still need to develop later iPhone etc apps. If you come from a web background this makes sense. There are good video's for quick learning. Good Luck
My experiences with Appcelerator seem to suggest they are more of an iOS shop. Their toolset for Android is, IMHO, quite lacking. ADT supports visual UI building and debugging on device, which Titanium Studio does not. There has been a bug filed about this for several months now, and it continues to be delayed. If your focus is Android, use Google ADT or MOTODEV Studio for Android. These IDEs are quite nice and are used by professionals.
The above answer presents a great way to develop mobile apps. DO NOT COMPROMISE ON A HIGH-QUALITY USER EXPERIENCE.