Having previously owned a Mitsubishi HC3000 and being relatively pleased w/its performance, I was following both the threads for the Mits HC3800 and the Epson 8100 for about 3-4 months before going with the 8100 in January of this year. Hadn't seen an overwhelming amount of issues w/bulbs in the 3800 thread, but there were a handful or so. Most of the issues w/the 3800 I saw were in relation to sporadic shutdown problems that many believe to be firmware related or early model issues, but I don't think there was any specific cause that Mits confirmed to causing this, not a big surprise there as I wouldn't expect it from most electronic manufacturers unless there was a recall.
Like any projector, they (the 8100 and 3800) are likely to have some model specific issues and whiile it may look like a large amount of users are having issues, it's difficult to determine without knowing the amount of projector sales worldwide and amount of repeat support issues without the numbers directly from the manufacturer, which isn't ever going to be known outside of the organization.
What might alarm owners or prospective buyers is seeing the postings on AVS and other forums. What has to be considered is the amount of users that aren't encountering any problems. Folks are generally more likely to post problems in hopes to resolve them than folks just simply enjoying their projector or purchase problem-free. Another consideration is users that may encounter issues, but never do anything about them nor contact support. Again w/out specific numbers for the amount of support issues reported and the number of projector sales, its really just speculation... -TD
Emotiva XPA-2, XPA-5 | Yamaha CX-A5000 | Mitsubishi WD-73742 | Epson 8700UB
Boston Acoustics VS 336s, VS 325c, Emotiva ERD-1s (x2) | 15" TC-2000 DIY Sub
Dish Hopper with Sling | Oppo BDP-93 | AppleTV v4 | Roku 3