Boilers have leaped in technological improvements in the past 10 years, and now that many of the manufacturers offer these boilers, the cost have been lowered.  The biggest changes have been in the condensing gas boiler market. Condensing gas boilers are seeing efficiency ranges in the 90+ realms, depending upon the water delivery temperatures needed to heat the space. Payback periods for these installations can be as short as 4 years. The comfort is great, and the increased efficiency allows the customer to dial in a temperature that is comfortable without paying a penalty for energy cost. I have had many customers spending more for energy and still not comfortable. These boilers solve that dilemma.