I have been using summit stands for 15 years and I do love them. However I saw this stand at a show this year and I was very impressed!! I want to try one and may sell my viper ss if I like it as much as I think I will!
http://www.treewalkertreestands.com/

Hang ons are great and I have several also, but having one protable for those situations that dictate mobility they are just indespenasble in my hunting arsenal. They allow you to easily change tree, height location with very little effort.