My general recommendation is that the HW40ES is a great projector for the money, but for roughly an extra $1000, I consider the HW55ES to be the better investment and worth the difference. I mention this now, because lamp life comes into play.
The HW40ES claims a very impressive 5000 hours in Eco-mode (aka Low lamp), but things start getting expensive if running the projector at full power where the lamp is rated only 2000 hours, which, these days, is way below average. For a “worst case” comparison, consider that the Sony lamp lists for $369, while the Epson 5030UB’s lamp lists for $249 (both get discounted), but the Epson lamp at full power is rated 4000 hours compared to 2000 for the Sony. (The Epson is 5000 hours, just like the Sony, when in Eco-mode. So, the point is, if you run in full power you definitely should factor in unusually high lamp costs into a Sony HW40ES purchase.
A reminder: Lamp based projectors do not calibrate the same in full power and eco-modes. Therefore, in theory, if you plan to switch back and forth, you would want both calibrated. We don’t do that, but I can say from playing with the HW40ES, that the out of the box color definitely isn’t as good in “eco-lmode” on this HW40ES I have here.