This ('kj') works great for me in User Keybindings with ST3 and Vintageous:

  { "keys": ["k", "j"], "command": "_enter_normal_mode", "args": {"mode": "mode_insert"}, "context": [{"key": "vi_insert_mode_aware"}] }

I was a heavy VIM user prior to making the switch to ST2 and then ST3, and haven't really found any vim blockers with ST3/Vintageous.