I found the following comparison:

http://www.xaraxtreme.org/about-performance.html

This makes having doubts about the performance of cairo on babelview…

Babelview’s goal is to provide a simple, no-bloat phone framework. Yes, it is 2010, and I think that bloat is not the answer for usability and feature. The principle of babelview is the more you want, the more you have to pay for it in terms of responsiveness, start-up time of applications. The goal is to boot a linux based phone on the reference platform “openmoko freerunner” in less than 10 seconds. I mean “boot”, to have the phone in a state where it is possible to make phone calls, or start applications.

The highlights of the “should be state” of the minimal babelview stack:

• simple widget kit that focuses on full screen applications
• full screen transparent keyboard for simple application manipulation
• simple and consistent gest recognision system
• own rendering engine (draw (line, circle, etc.), draw string
• jpeg viewer with basic transformations
• pdf viewer for document viewing
• ebook reader
• navit navigation, map viewing software
• web browser
• powerful and fast text editor (the new viq) engine