Is it feasible to pursue PhD with BE Degree/16+ years of experience, and is it worth it? Is it possible to pursue PhD with only BE degree and 16+ years of Software Industry experience? I know that most of the institutes expect a Masters degree to pursue PhD.  Do they consider Industry experience to relax this criteria?

And, then the big question - Is it worth it to pursue a research/academic career after 16 years in Software Industry?  Has anyone done this? what are your experiences like?
Your assumption depends on your location. If you are interested in obtaining a PhD in Computer Science at a school in the US, then in fact many programs do not expect you to have a Master's degree prior to beginning your doctoral studies. However, if you've been in industry for 16 years, it may be difficult to secure the letters of recommendation required for entry. Certainly letters from employers are accepted, especially in your case, but if they do not show a strong desire and aptitude for research, they will not be worth as much. However, don't let that dissuade you. Apply anyway, if that's what you want to do.