As Tanith and others have said, the automatics score in heavy traffic, or just tootling round town.
BUT -- if you transition to one, having driven a manual for many years, you might in a slightly distracted moment (and we can all have them) press on both 'clutch and brake pedals' together (as you've done so many time over many years), and find you've actually in THIS new car pressed heavily on the brake and accelerator (the only 2 pedals of course!), resulting in a surprise emergency stop!
[I'm referring to the UK pedals layout. So, keep what was your clutch foot out of the action - perhaps if that's the leg with what is now a dodgy knee the process is easier?!]