In the interest of accuracy, from the Voodoo Labs website:
It was their claim to fame for years, so I believe they do a good job. Does the MXR do as well or better? I guess we'll find out.
For me, a wall wart is another possible point of failure - it can come unplugged, the cables tend to be easily broken, etc.
It's not quite a deal-breaker, but it's a big negative (again, for me).
The PP2+ has proven itself many times over as far as reliability and sturdiness. I just bought one used before I heard of the MXR, but anyway it has everything I need for now, so I'll wait and see what happens over the next couple of years before I jump onto something new. I'm guessing Voodoo Labs will come out with something to compete with the Iso Brick, or lower their prices or something like that.
I view it as if something is not broken, don't fix it. Everyone I know is either using Iso 5 or Power Pedal 2 including myself and they are built like a tank. I decided to go with an Iso 5 instead of the MXR Iso Brick. The wall wart and lack of tour testing was a deal breaker for me. Maybe in 3-5 years when I need a new one.