Hats off, O'Neill is doing excellently there.
You can see though it's all down to his man management. The way they play, there really is very little to be intimidated by. Sessegnon and maybe McClean is all they have who you'd expect to cause problems running at players. The rest are mostly just varying degrees of cloggers.
They've infinitely improved from the end of Bruce's reign (not sure it could have got worse) and with a mixture of O'Neill's management, renewed belief and a fair few lucky moments, they've put together an excellent run. Question remains how they'll cope when a few things eventually start going against them.