Hi Andrei, I have a 3 year old (almost) Ti
Observer.
Your observation is correct, the buttons are not Ti, Ithink they are just stainless. Everything else that is metal does seem to be Ti including the clasp etc.
The finish seems to wear fine, I wear mine everyday from climbing to the office and it still looks great!
IMO, the Ti looks much better. One of my climbing partners has the stainless version and on the wrist you can fel the weight difference, if that is a concern of yours.
Good luck with your choice (if you have not made it already)
krak