Rowland Model 112 or Simaudio Moon W5

I've had the Rowland for a decade, and often joke that it took half-a-decade to break in. Discovered that it requires a few simple tweaks to unleash it's potential; replace the footers with something more robust (in my case carbon graphite `TuneBlocks' from Boston Audio), place on a nice heavy amp stand, ensure that your cables are on the lively side (the 112's highs can be a bit reticent), and use the balanced inputs if possible. Even though I've tried a few different amps over the years, I keep coming back to the Rowland, it is a nice piece for the long haul.

Note, however, that I have no practical experience with the Sim.

The Rowland was a warmer sounding unit in the system I heard it in. The Sim sounded more extended top and bottom and lacked a little sweetness in the mid-range in direct comparison. Either amp is excellent.

Buy them both and resell the one that comes in second.