My folks got the Atlas 12s last year, and they seem less intimidating and possibly more comfortable than my MSR Lightning Ascents. Simply put, they are 100% reliable in all snow conditions, classically designed, and you'll never need to buy another pair.
However, I went with the MSRs because I wanted the more aggressive frame and removable tail option. Also, the pointed tail on the Atlas 12s kicks up an incredible amount of snow into your butt (could be the spring-loaded suspension?) leaving your trousers uncomfortably soggy. This would be an even bigger problem if, like my mother, you plan on snowshoeing in bluejeans...