I was looking for a wheeled, carry-on sized bag with the convertible backpack and was comparing this High Sierra model with the Eagle Creek Switchback Max 22.  I ended up going with the High Sierra model basically because it offered the same basic features for 75% less cost.  The quality is good (although not quite on the level as the Eagle Creek & not the same lifetime warranty) and it seems very durable.  The backpack zips on and off easily, and it was a breeze to carry on.  The backpack strap feature on the main bag is nice to have if you are taking your luggage through busy city streets, lots of stairs, etc. and it's easy to use too.