Update to Reply: I'm very glad you're taking note, since I'm under the impression that Yoga Tree has a lot of potential, with a strong management and exceptional instructors. However, the class I took with my friend had much less space than 2.5 feet between mats, and this wasn't the class you are referring to as my last.
This update has been a long-time coming.
It really bothers me when yoga schools go against the basic teachings and philosophies of yoga and turn it into a money grabbing institution.
My favourite? When evening hot yoga classes are greedily crammed in with so many people -yogis don't have enough space to properly do all positions.
A health hazard? Maybe.
Yes, they have a range of classes by skill now, but it looks like it has come at the expense of a great experience for the yogi.