Quartz 2D or OpenGL ES? Pros and cons in the long term, possibility of migration to other platforms

Question

I'm having a hard time deciding whether to go with Quartz2D or OpenGL for an iPad game. It will be 2D mostly, but effect-intense (simultaneous lighting effects for 10-30 objects, 10-20 simultaneous animations on the screen). So far, assuming i'm equally dumb in both technologies and have to learn them from the ground, i came to this list. (I've read several topics here, on SO, with names like "Quartz or OpenGL", but i'm still left with some questions)

Quartz:

• Better time-to-market, because of ready to use absractions like UIView, UIImageView, CoreAnimation abstractions

Open GL ES

• Closer to hardware, thus, performance is better.

• App, implemented with OpenGL ES can be easier migrated to Android, MeeGo, Windows Phone, etc.

My questions are:

1. How time will it take to rewrite Quartz 2d app to use OpenGL? Lets say it took me 2 man-month to write Quartz app, how much time will i need to rewrite it? (Please, just some subjective opinions, i'll try to summarize them somehow)
2. Regarding the ease of migration to other platforms, when using OpenGL, is it really so? Or efforts when migrating Quartz app from iPhoneOS to Android will be not so much bigger, compared to OpenGL app migration? (Ease of migration is quite important criterion)
3. Regarding OpenGL, should i go with OpenGL 1.1 or 2.0, concerning migration? (Android supports 2.0 through NDK, but dont know whether NDK's use will increase or decrease migration efforts)

Answer 1

use a framework that is cross platform

Cocos2d for android: http://code.google.com/p/cocos2d-android/

Cocos2d for iphone:

http://code.google.com/p/cocos2d-iphone/