If I were buying a PJ from scratch, I would definitely get a 4K or at least a 4K-Enhancement PJ like the Epson 5040UB (5,000 lamp hours in Economy mode).
"Compared with standard 1080p models like the
Sony HW45ES and the
Epson Home Cinema 3900, it offers visibly superior resolution and image quality."
"wWhen compared with current native
4K projectors, it delivers nearly as high quality an image."
http://www.projectorcentral.com/epson-5040ub-review.htm
Laser sounds enticing, but the cost difference is significant on top of 4K.
I've changed plenty of PJ lamps. Just changed the lamp in my BenQ 3 weeks ago. Easy stuff.
So these Laser PJ will last about 20K hours. What happens when the 20K hours is up if you can't replace the lamp? I guess you'll just have to replace the whole projector after about 10-13 years, assuming your laser projector lasts 10-13 years.