When you target Flash, the normal display list uses a software renderer, while Starling leverages Stage3D, giving hardware acceleration. On mobile (especially) this makes a performance difference. OpenFL on other targets (such as HTML5 or the desktop/mobile native targets) uses OpenGL for hardware-accelerated rendering. This can perform better than ordinary Flash for regular display list projects.
OpenFL added a
Tilemap API that is like quad batch API, designed to feel similar to the ordinary display list. If you reach a performance bottleneck and need additional performance optimization, this (or other approaches) can be good solution.
Starling in Haxe uses Stage3D on Flash, and Stage3D on OpenFL. The downside is this will not work in HTML5 canvas or Cairo on native platforms, which we use when hardware acceleration is not fully available in the browser or on desktop platforms. Most of the time this isn't an issue, but it can affect supporting older hardware.
Starling is not fully ported. Ultimately, so long as you do not rely too heavily on
BitmapData-based rendering or
sprite.graphics, you can get hardware acceleration either way, so I would recommend what you prefer.
OpenFL includes a BunnyMark sample that might be helpful for benchmarking. The Starling demo also includes a benchmark