@Sandro,
I've got nothing bad to say about Big Phil as what he's building is a great smoker for a great price. That said it's definitely not on the "higher end" and it comes with limited customization.
@cmtd,
Both of those smokers will function quite well. Personally, and I can't say for sure whether or not it matters, but the firebox on Outlaw is quite small. I've never heard anyone say anything bad about how well these draft or anything of that nature. That being said the small size limits the size of splits you can use, and I'm one of those guys who prefers an oversized firebox to a small firebox. The Outlaw firebox is double insulated so I understand why they have gone with this design.
Mill Scale is definitely on the high end with how they make their hinges and all their "finish" work. They are also on the extreme high end when it comes to price, but you get what you pay for. I will mention that castors can be a pain, and I'm not seeing an upgrade option to golfcart wheels on the MillScale page (though I'm sure they'll give you that option if you call).
It really comes down to style ; traditional "Texas style" offset versus "competition pretty" offset. Obviously shipping is something to consider as Mill Scale is in Lockhart, TX, and you can get an Outlaw through a dealer in Kansas.
I'm not sure if you're interested but Shirley Fabrications is very close to coming out with their "direct flow backyard model." In terms of high end that will definitely be right up there with Mill Scale.