I had an Espar in my Tartan 37 and everyone loved it. Even in the summer it came on briefly in the morning just to dry things out.

My second choice would be a Wallas Diesel stove. I had one in a few of the boats I've owned and although not an Espar, it does provide nice radiant, dry heat but takes a quite a bit longer to both warm up and cool down if it gets too hot. The added benefit is cooking on the same surface that heats the boat.