OK, received 2 Blue Pops today and installed them. Sorry for the crappy pics, was trying to do all while trying to meet a work deadline
Build quality is pretty good, feels pretty solid. As you can see, the backside of the bulb contains the heatsink as pictured below
They went in perfectly, fit is perfect. As far as color goes, wow they're very blue, you can see them below on Ch 1 of my ATI fixture
I did notice that they do tend to "sag" just a little, you may be able to see this on the left bulb in the pic below. Nothing too bad, but I've read about this in some forums. Doesn't really bother me.
Now for color, here's my grafted monti frag under blue only (sorry for the crappy pics)
You can see the color difference a little better in the below pics.
Before the Blue Pop
After the Blue Pop
So far, I'm happy with what I'm seeing....what do you all think?