No regrets.
Not having an income was a bit scary at first, but I got used to it pretty quick.
Kind of in the same boat with you... left the corporate world at 49 (12 years) ago and am 61 now. Had some consulting income until a couple of years ago, but pretty much just rely on investments now.
I'm hoping to hold off on taking SS until 67, or at least 65 though... I'll just play it by ear I guess and see if I need it or not. I have to get through 4 more years of paying my own health insurance, and that's a big unknown as to how expensive that will be in the next few years (already bad enough!).