I am using some Atlas machines that I used on my layout 40 years ago. That's not continuous service, of course, because they were all packed away in boxes for most of that time, but they are a good 40-50 years old and they are still working. They've been moved from their original brass turnouts to new nickle-silver ones, of course, which says something else good about Atlas - their parts stay compatable for a long time.
But...they are ugly. I hate the way they look. I've begun making scenic covers for them so I can't see them, which is a lot of extra effort. Atlas does make what they call "under-table" machines, but the throw rod is only an inch long, so that's as thick as your table + roadbed can be. Since I use 2-inch foam, it doesn't work. I did take one of them and glue it to the underside of a turnout, which I then put down on the layout. So far, so good, but if it ever fails I'll have to rip things up to fix it.
The thing about Atlas turnouts that is unreliable is the pushbutton controller. They have a habit of sticking, and if that happens at the wrong point, you will melt your switch machine. I replaced all of mine with simple SPDT momentary toggles.
In some places, I'm using Peco turnouts and switch machines. These mount easily right to the underside of the turnout, but they do require a hole in the layout to fit into. I cut the hole all the way through so I can (maybe) replace one from underneath if necessary.
Tortoise machines come with built-in auxiliary contacts for signalling or indicator lights. You can buy an accessory for a Peco to do the same thing for a few dollars. Atlas makes a "deluxe" switch machine (under-table only, I think) with contacts, but of course that's more expensive, too.