Hi Matyam,
I actually just replaced the bulb in my 5700 (1900 hours on previous bulb) and it has cetainly breathed new life into the old girl. The image is bright and vibrant once again. Saying that, after 6 years I'm also considering upgrading. I Purchased the new bulb for resale value.
My two requirements are at least 1000 lums and long throw capability. The two projectors I am considering are the JVC HD350 and the recently accounced Infocus SP8602. There is a thread all about it
Here
I'd be interested in hearing what you end up with.
Regards,
Stephen