The 2010s' 75W rating is probably a really nice match w/your Harbeths (BTW, the Exposure is a beautiful piece), and I'd say you would have to make a significant power/current jump to tell a real difference. I use old NAD pre/amp w/my Spendors, and although they are circa 1992, the combination is beyond good...balanced, smooth, and quiet. You may want to try a used NAD 272/162 combo for more current, dynamics, and low-end control. You could snag these for less than $800 on the Gon, and they may surprise you. Or how about a Parasound A21 and NAD 160 or 162? Could be another involving (and versatile) set up.
Advice on switching to separates
Currently using an Exposure 2010s integrated amp with Harbeth mini monitors. I am absolutely satisfied with the overall performance but have always been wanting to try separates. My question is can i better my integrated with separates on a budget of around 1500 dollars. I also have Omega super 6 Alnicos speakers from a second system which was scrapped. Due to space limitations I now use the Harbeths because they are smaller, but they can be switched back in if I can put together a system that beats the one I currently have. Any suggestions or should I be happy with what I have. Thanks.