Hi Gaz,
I have the middle sized scrubba, but haven't used it much for years as I use a t/m most of the time, it is a good tool but i found it too clumsy for domestics and I tend to work really fast so a wand is more my thing anyhow,
I would only recommend one for large heavily soiled areas like restaurants etc and prob would not bother with the mini but go for the bigger one,
As for agitating I would favour the oreck orbiter more or a small rotary,
I've had sebo duos in the past but they are very lightweight and tend to break easily ,
I tend to use just a pile brush when needed on domestics now as I need the exercise

Regards
Steve