I've been firing up the Z4 for 8 years now. Something I didn't plan on happening, but it still works really, really good. In its life it has only seen two bulbs; the original bulb and the replacement bulb that came with the unit as a promotion. I'm not even sure which bulb is in it now, since I've switched back and forth a few times or more. I do have to bump up gamma and open up iris to get enough brightness out of the dimming bulbs, but otherwise the projector works like it did 8 years ago. I've always been extremely satisfied with the color accuracy and content with the black level which looks damn good considering it is older technology. I use it for blu-ray and it is connected to my mac mini so I might watch OTA as well as web content. The video processing seems better than my flatscreen. Having said all of this, obviously I can't be completely satisfied with this aging unit and its 720p panels and its slight screen door effect.
Yet, I'm at all sure what to replace it with. It is on a rear shelf so I must have lens shift. It is in a totally dark room, although unfortunately the walls are white and there is not much i'm allowed to do about that. The only new projector I feel I would be happy with overall is the Epson 5030ub. I wish there were less expensive options. Anyone have some ideas you wouldn't mind sharing? And does anyone else still use a Z4?