It was fun being able to pick up things like screws and small parts, and it was cool being able to feel when a laptop was about to slow down as the fans and sometimes hard drive spun up.
But I have to be honest, it was also stressful in a weird and latent way that I have trouble describing.
For one thing, my body can deal with a lot of problems, often without any sharp alerts that it is doing so. I accidentally cut myself? No problem, it'll be fine in a day or two. Whanged my elbow on a corner and bruised it? Not a problem. But if I slam the magnet in a drawer, that could easily require a trip to the ER and maybe even a lost or damaged finger. My body didn't care about its inert coating, but I doubt the immune system would appreciate a large disc made of neodymium, boron, and nickel.
Even if that weren't the case, I'm not sure if I could have stopped being aware of it. It was very solid, and its presence was almost insistent. Other attempts at taking advantage of haptics and neuroplasticity, like wearing garments with sensors and vibe motors all day and night, didn't give me the same sort of apprehension.
I never ran into any problems or pain with the implant, but when I eventually got it removed after a few years, I still felt enormous relief. The tech told me that the new ones are basically slivers which were much lower-profile, but it'd probably still lose its magnetism over time and they also said that they wouldn't have felt comfortable trying to remove one that they couldn't easily find.
That's just mildly interacting with what I guess you could call the "application layer" of my body. And people are seriously discussing things like cryogenics and brain uploading? I could be pessimistic, but it seems unlikely for this generation. Better to just keep striving for the benefit of those that follow, don't you think?