I can answer some of that, but I'm a teeny bit biased about which is best, because I'm a HoC consultant.
Basically both systems aim to help you find the palette of colours that works best for you. At HoC we do this by comparing a series of different toned drapes to first assess whether you have warm or cool skin tone and then to assess whether you need richer/more muted colours or clearer/brighter colours. We then show you the make up colours you can wear that will make you look your best, and spend some time talking about exactly how to use your swatch book to shop/sort your wardrobe/generally feel amazing.
People use the information to different degrees - a lot of my youngest clients will keep it in mind purely for something like a prom dress, many many clients will adopt it as a rule book for every aspect of their wardrobe (makes things like capsule/perfectly co-ordinated wardrobe very very simple if everything mixes and matches, colour-wise), and some people fall somewhere between the two, where they will make sure that any tops/scarves are good colours, but might not obsess too much about making everything in their wardrobe perfect. Pretty much every single client says that (a) it isn't as limiting as they thought it would be, as there are so many colours within each palette, that actually it gives them more ideas rather than limiting their choices, and (b) the whole process is more interesting/life changing than they expected it to be.
It shouldn't be too tricky to stick to, as you'll have seen exactly what the right and wrong colours look like and how to shop with your swatch book (at HoC we are determined that as far as possible the client sees and understands it too, rather than just being given a swatch book and marched out the door with very little further information).
At HoC a colour analysis is a 3-5 hour class usually, with anything up to three other people, the vast majority of my own classes are 2-3 people.
Sorry, that was a bit long!