Originally Posted by POW R TOC H
Somehow it seems to me that I the small boost I will get from using the array method will be lost if I use shaders and triangles.
Well, it won't be lost (you'll need just vertex shader, not pixel), but this system will need a lot of redundant data to work.
I implemented such thing on DirecX many years ago when I've run into troubles with pointsprites (maximum size limit, no rotation, etc) in 3D particle system.
Implementing what I've described makes sense only if you need large quantites (over 1000) of really large (possibly larger than screen), rotating, perspective-corrected textured sprites acting as particles. If you are using points and they are sufficient for your task, then writing this will be (probably) a waste of time.