I've had two Whitten's, they are real nice cases. They are are very sleek, and stylish, damn near perfect. My only two complaints are, as shamadam mentioned, that strap in the middle definitely tends to slide off the shoulder WAY too much, and the spacer system they use could use some improvements. Man I wish I knew about their lite cases, and the fact that you could order a diagonal strap, or one on the side before I had ordered my last case. I think I may have to order another one with those options. And as far as the spacer system goes, it's no biggie, the spacers kept coming out of the case stuck to the bottoms of the butts of my cues so I just glued them in permanently. I think I am going to sell my case and get one of those diagonal strap ones.
I think ultimately your choice may come down to price as well. I've heard that Murnak's are VERY nice cases, the top of the line. But you're also going to have to pay for that. If I'm not mistaken, they're almost double the price of a Whitten.

That's the only thing that stopped me from getting one. I couldn't justify spending close to a G or over for a case! But if money's no object, you might want to get one. For me though, you can't beat the price and quality you get with a Whitten. I think someone else mentioned also, their turn around time is real quick too, like only a few weeks.