The VSX-919 runs warm/hot. Hard to describe how hot but Its much warmer than the AVR 590 (which I am also running now). The Denon "barely" generates any heat. I think the 590 would apply to the 1610.
However, if you read the threads on both models most of the experienced audiophiles do not appear worried about the heat generated by the 919 especially if you have proper ventilation.