When I had the C1's I had a Bryston B100sst then later an Octave V70se and V110. All sounded great with the C1's. Naim is another that mated extremely well with C1's. As far as Sim I thought the sound was too analytical. I found myself listening to the equipment and not the music.
That said are you looking at or have original C1's or the MKII/Sig or Platinum? With the original they sounded the very best when you turned them up. The louder the better. When I got the Signatures the best part is they sounded a lot better at mid listening levels. So I can see where some folks would say they need a lot of power when comparing to the originals. IMO the C1's have a great price to performance ratio. The Dyn stand2/4/6 is also a must.
That said are you looking at or have original C1's or the MKII/Sig or Platinum? With the original they sounded the very best when you turned them up. The louder the better. When I got the Signatures the best part is they sounded a lot better at mid listening levels. So I can see where some folks would say they need a lot of power when comparing to the originals. IMO the C1's have a great price to performance ratio. The Dyn stand2/4/6 is also a must.