@Jay: Menu class has been replaced by Menu Attributes on D7 and we have used that one on rare occasions. Mostly we just use this when there is a unique design that warrants the extra control over the menu. What do you use it for?

Also, we aren't fans of Panels. We use Display Suite when similar functionality is needed. Panels has caused issues for me in two ways ... 1. it was more challenging for clients to edit content, 2. it didn't play well with several other modules (like Meta Tags) On the other hand, I've been very pleased with Display Suite.