So legacy means "deprecated".
Learn to walk first, then run. Also, acceleration when it works on one family of graphics devices, will run unaltered on pretty much the whole range.Exactly. Acceleration is much harder get stable than modesetting. How many stable 3D drivers are there compared to drivers that can get a picture on the screen?
But do keep this story up. I'm sure that in different circumstances you will start saying the exact opposite.