From my experience, AHI v5 strangles the 680x0 to death. It used over 40% of my 040 just for a single stream from AmigaAMP. None of the old fast modes are available which were perfect for simple streaming applications (IMHO).
So, running AHI apps made my system sluggish and unresponsive with v5.
It actually took me a while to realise what was causing my system to lag so badly. Going back to 4.18 shed the ball and chain and made my system snappy again.