It is a really fun stack. The book Mnemonica comes with a lot of great advice for learning the stack. It claims that you should be able to learn it in about 3 hours.
I however, spent quite a bit longer then that learning it, but the time really paid off. It is one of my favorite things to use in card magic. There are so many possibilities, so many simple ideas, long ruotines, mind blowing effects etc...
It definitely takes a lot of dedication, but you will be happy that you put the time into it.
I do recommend that you purchase the book, and not just the learn the stack. The book is quite expensive, but the amount of material in it will last you a long time.
Have fun =)