Cleland,
We've used a fair amount of Atlas with varied results. He works best on cows with a lot of power. We've only kept one Atlas female and she will have her first calf in March, so I can't comment on how his daughters work.
We've also used some Landmark with mostly good results. He will typically sire cattle with a lot of power. In our limited experience I feel that he works best on cows that are prettier fronted and/or refined. When bred to females that aren't quite as refined, the calves will be a little course and/or have too much leather up front for most of our customers' preferance.
We've had a couple Landmark calves with white on their faces (both times it was a spot or heart shape between the poll and eyes). I know that several of Knoll Crest Farms Landmark cattle have also had some white on their faces.
Jmichal, I'm a little confused by your statement about having Atlas in your herd from Advantage. Atlas is a Cocoa son out of a Premier cow, and Advantage is a Premier son out of a Tom Horn cow. Just curious what you meant.