I have never did dead lifts nor squats with a smith machine. It is great that you are expanding and experiencing new exercises. Those two exercises are great, but to benefit the most out of both, use free weights. In my opinion it is really hard to achieve perfect form when the bar is stationary, unable to really follow your formation.
Be happy that you tried something new and no it is not crap. In my opinion the potential for injury is higher with the smith machine than the free bar. Give the free bar a try and you will notice how different your form must be and how much more beneficial it will be.