Whether someone decides to upgrade or not is really up to them, a personal decision with personal factors. However, I think you would be hard pressed to find many people here who would not agree that Platinum has become more stable, better-performing and obviously more feature-rich than X3 ever was; in any case that's very much been my experience, and from what I've seen on the forum it seems to be the consensus. Doubtless there are those whose experience or opinion differs, and I've not done a full and formal survey on the subject, but from my impressions of the general tone around here, that's what I've noticed. Perhaps it's just confirmation bias, but there's not much any of us can do about that - human perception is what it is.
Also, I'll second what Bruce (tenfoot) said above. The OP's computer specs are not exactly cutting-edge, which can contribute to problems. That said, Platinum runs smoother and more stably on my old machine (Q6600, 8GB RAM) than X3 ever did, by a healthy margin. Plus, it's fully supported. So yeah, there's that... do you want to solve your problem and get back to work, or do you want to draw a line in the sand on principle?