I bought a Philips bare lamp for my Sony Pearl, worked out just fine at a fraction of the cost.
The problem was the original housing was so brittle from heat, it was almost impossible to re-use it, but I did make it work.
Shortly after I sold it on eBay, the lamp stopped working, something went wrong with the housing, I ended up knocking off a 100 bucks from the sale when the seller got a new housing from the Sony store.
I went to great lengths to keep my perfect eBay score.
I think these bare lamps are like car parts, you can buy a genuine Ford fuel pump from around 400 to 600 bucks and it will last for a very long time, or you can buy a cheap one for a 100 bucks and it may last less then a year or longer, there's no quality control on the cheap stuff.
If something goes wrong with the Ford part, the defect can be traced back to where the problem started, that's what makes it so expensive and it's this quality control why the Ford stuff very rarely fails.
All the parts are tested along the way to make sure they function as they are supposed too and it's all that testing is what makes it reliable, if a problem shows up, then it's caught before it gets to the public.
I believe the same can be said for these bare lamps.
Ushio may fill an order for JVC and purchase 10,000 lamps and in fact JVC more then likely has Ushio build the housings too, as with the genuine Ford parts, they are tested more extensively to function to a higher standard before the JVC logo is put on them, weather that is on the box, or housing or both.
So when one buys a relatively inexpensive lamp, it may be genuine, but I believe that quality control is lost.
I bought a lamp for my old Panasonic 4000 from one of these on-line retailers that sold only lamps, some with housings, some with out.
The bulb was genuine, so the logo on the bulb said, but the housing was made out of this cheaper plastic that smelled like burning Styrofoam.
When I confronted the place where I bought the lamp from, they said "the smell will go away", it never did, so I ended up reusing my old housing.