I have a Mac 220 pre (Ayre V1xe,Silverline Grand La Folia, Ayre CD5xe) and a friend have a Ref 3 (DIY Orion,ATI amps, Reiymo CDP). We changed preamps for some days. In my system ref 3 has more warmth, more bloom and a fantastic big soundstage almost like surround. Mac was more accurate, more neutral and it has tone controls (which I like). I sligtly prefered Mac thinking that ref 3 was to warm. But I still missed that big soundstage.
In my friends system my Mac was clearly superior giving a more accurate and correct sound.
The 220 pre cost about half as much as the ref 3 so I think it is very good value. I have not listen to the Mac 1000pre.