After almost 10 years of ownership and 6500 hours of use, my HD-56FH97 finally started displaying a message that the lamp needed to be replaced. I had an original JVC lamp on hand that I had bought a few years ago, so I just installed it and kept the old lamp as a backup.
The new lamp makes a huge difference! The TV is so much brighter than before and the colors look better. I actually turned the brightness all the way down for now because it's so bright. I should have installed the new lamp sooner, it was very easy to do.
On the downside, my JVC has unfortunately developed the dreaded "yellow blob" issue over the last 2 years. The lower 1/3 of the screen has significant yellow tint, mostly noticeable when showing screens with white or grey in that area. It's really unfortunate that this otherwise great TV has this fatal flaw. It's probably some cheap plastic lens or filter that gets discolored, and kinda ruins the whole set. If only JVC had chosen a different material for that part.
Oh well, I'm not too worked up about it, since this TV got moved to the bonus room a few years ago, primarily for video games. I still feel like it served me well, and was definitely the best option available at the time.
My main TV has been a Panasonic plasma for the last 6 years. I was a bit reluctant to replace the JVC at the time, but am sure glad I did. I love my plasma, and hope it will last until OLED is affordable.
I just checked the hours on my plasma (purchased in 2011) and it already has over 6800 hours, and the picture still looks as good a new. Both TVs cost about the same, so the technology definitely did improve.