I *think* the Mio has a 600D outer and the Hero is 1200D. I don't like the new Amigo rugs personally, don't think they're worth the money. Even the Hero feels cheap.
It's all about Swish Equestrian now!! Cheaper than Amigo, far better quality and the fit is superb.
I literally just bought the PE 600D lite T/O as they have 20% off today, went on to Swish and their 1500D L/w is even cheaper! Doh, too late now! It's in the sale if anyone interested .