Yup, its a fast way and only marginally slower (2 scanlines) than using longwords, defo faster than the original method, I did not think it would be so close to longword speed in this instance. The method I mentioned altering the buffer format and using longwords is going to give a little more (45 or just into 46 scanlines) but there is the buffer format change to think about which might cancel that out plus more.

In my years of experience I know using longwords is the maximum for speed when copying memory around but I did not realise that sometimes using movem with words can get you almost as close in some situations so I learned something from your initial idea Dresbenboy. Maybe you learned that with movem its sometimes good to use an address register (indirect with increment) and not as storage . And blaster has been taken out of the world of move.l (a0)+,(a1)+ and introduced to the world of movem. We all gained something and that's good for everyone.