I've had some bad smells from wood with bark on it, and I'll sometimes pre-burn the bark a bit before setting them in the smoker.
Given a choice, I'll take only bark-free heartwood.
Whether you believe bark can be bad or not, the effect will be pretty short-lived depending on your smoker. With a stick-burner it will go real fast and with charcoal too, but in an electric and at lower temps, the effects will linger.
The best answer is to test your wood - if you don't notice anything bad, then use it.