I did the Gina Ford routine, like a slave, with ds1. I think it was because I had no idea what to do with a baby and needed the guidance but I was a bit obsessed with it, I consulted the book for everything!
It was a godsend for me though as I was suffering depression which I wasn't really aware of, so it did keep me focussed on ds1.
I got a bit more relaxed about the nap times as he got older, and more focussed on reading the signs from him, I knew that I needed to get him down after about 3 yawns or he'd be over tired, that sort of thing. You can plan things around the naps most of the time and then if you don't do the routine for one day, it's easy to get back into it.
I was much more relaxed with ds2, it's very difficult to do her routines with 2 children, but I kept the basic routine of the naps, they may not have been at the same time every day but near enough.
The thing her routines don't take into account is what your baby is like, I had no idea at the time, but ds1 is 9 now and he can be bad tempered in morning and still needs his 11 hours sleep or we all suffer.