I had my neobladder surgery in 1997, so now well over 21 years.
Recovery for the first 7 months was tough and initial continence was poor for about 2 months and a bit depressing, but then magically I mastered it. So persevere through the early problems. Since then I am 100% daytime and over 99% nighttime continent, so I think you can say I am a success story.
I have never had to self catheter.
Only two real blips. One is that over the last two years I have seen an increase in nighttime leakage. Not terrible, but definite change, which I was warned about as I got older and my muscle tone reduced, or if I get so tired that I don't wake up on schedule - which for me is close to 4 hours. Daytime remains 100%.
The other blip has been a few scary incidents of excessive blood and blood clots in the urine. Maybe about 4 times over 20 years, and each time lasting a week to 4 weeks. Investigations each time has shown they are almost certainly due to irritation set up by over-stretching of the neobladder. I seem to have one area of slight weakness in the neobladder which might inflame when over-stretched. So one lesson is to be careful abut over-stretching. Not as easy as it sounds to always be rigorous, and some of it is caused by over training of the sphincter muscles, which sometimes make it hard to empty. Basically, you get so good at holding it, that it gets hard to release the muscles, and the result is a trickle which you can misinterpret as an empty bladder.
When the bleeding happens I take antibiotics to stop it becoming a rampant infection, and rest and drink a lot of water to flush everything out, while staying careful about emptying. Bleeding can be scary when you have a bladder cancer history, but usually this gets me back to normal in a few days.
Other than that, life has been good on a neobladder!
One thing that can be a nuisance is that you will constantly be misdiagnosed by non expert physicians as having a urine infection. You learn to ignore that, and make sure you stay in touch with the expert that did your surgery or equivalent for best advice.