I'm 75 now, and my hearing loss has also been around 30 years or so. I now have bi-lateral CIs. I got my first implant 15 years ago and the second just last year. The difference is profound and mazing, but not free. Your brain doesn't completely recognize the new information sent by the implant, so you have to sort of re-learn how to hear. It took me a couple weeks to be able to get basics (anbient noise like the dog barking and familiar voices like my family). Fortunately, my brother also has CIs and had had them for years, so he could coach me thru the beginnings. I learned that the brain is amazing, my hearing just kept getting better and better. Today, my speech recognition in the longer-implanted ear is 92%, in the newer ear 64%. I think this experience is unusual, but I now know lots of people with implants, and everyone had the same experience with gradual imrovement.
It's very scary to face a surgery that's irreversible. I need cataract surgery and have stalled for years. Just can't face it, or at least not so far. Good luck with your decision.