I am a CPA in a tax practice. I am also currently studying for Level 3. Somebody asked me how the CFA exam compared to the CPA exam. The two are difficult to compare, for many reasons. Nonetheless, here’s my take:
—Scheduling the Exams—CPA is MUCH easier—
With the CPA exam, there are four sections, and you can take them in any order you want. You can take as many as you want in a quarter, but if you fail, you have to wait until next quarter to take the exam again. That means that if you fail a section on March 31, you can take it again on April 1. And since these are computer-based exams given at the local Sylvan Learning Center, you can always reschedule if you get sick, want to go on vacation, or just don’t feel ready. 
With CFA, you can take it on June 1. If you don’t want to take it on June 1, you’re welcome to wait until next June 1. That gives you a whole year to:
forget everything you learned (if you failed), 
get distracted with a new job 
get distracted with a new family 
move to a different city 
have a car wreck or other disaster, 
get depressed about your failing score. 
This makes the CFA exam exponentially more difficult, both because of the unforgiving nature of CFAI, and the fact that you can’t just study for a few more weeks and take it again. (I should know–I got score band 10 on Level 2. If I could have studied 2 more weeks and taken it again, I’m sure I would have passed. But I had to wait a whole year and study for a whole year to take the test again. ) 
—Candidacy for the Exams—CPA is MUCH more difficult—
With CFA, if you have a Bachelor’s degree, you are qualified to take the exam. Doesn’t matter what degree, what major, what school. A Bachelor of Arts in Art Appreciation from Local State University is good enough. 
With CPA, requirements vary from state to state. Most states, however, require:
a Bachelor’s degree, PLUS an additional 30 hours (for a total of 150 hours), 
30 of the 150 have to be in upper-level accounting, AND 
another 30 of the 150 have to be in upper-level NON-accounting business courses. 
This makes the CPA candidate fairly prepared for the CPA exam, even though they haven’t even registered for the exam yet. In my experience, almost all undergrad accounting courses teach 100% to the CPA exam. I don’t know if that’s by design, or if that’s just the standard body of knowledge for an accountant.

the hobbit approves…thats helpful thanks mate…what do you think about programme content?

—Depth of material for the exam—about the same—
Personally, I have not found any single item on the CFA exam to be terribly challenging. Pension accounting was challenging, but then again, pension accounting is also on the CPA exam. Business combinations can be tricky, but that’s also covered on both exams. Swap valuation on CFA Level 2 was hard. But it’s not any harder than partnership accounting. 
One thing to remember, too. If a person is simply eligible to take the CPA exam, they have already learned about 90% of all the information they need to know to pass the exam. They just need to refresh their memory. When I studied for the CPA exam, it was more of a review than actually learning new concepts. 
All in all, I would say that the CPA exam material marginally easier than CFA exam material. But that’s not the whole story. Read on. 
—Breadth of material for the exam—CFA is exponentially harder—
Even though the material is a little easier for the CPA exam, the CFA exam is probably four of five times more difficult. For example, I studied about 200-250 hours for my whole CPA exam, not including 30 hours of college work. I probably studied 200-250 hours for Level 1 of CFA. I studied probably 400-500 for Level 2, and I plan to study about 300-350 for Level 3. 
Also, each level of the CFA exam covers the same breadth of material as all four parts of the CPA exam combined. It’s hard to store all the material at once. Let me provide an analogy. 
In the book “Animal Farm”, the horse Boxer tries to learn the alphabet. He’s able to learn ABCD. Once he learns ABCD, he moves on to EFGH. However, after learning EFGH, he realizes he’s forgotten ABCD, so he has to learn ABCD all over again. After learning ABCD, he has forgotten EFGH again. He finally gives up on EFGH, and just decides to stick with ABCD. 
The CPA exam can be broken up into 4 small parts. Moreover, the material is exclusive to its own part. In other words, once you learn ABCD, you can forget everything you learned and move on to EFGH. Then you can forget EFGH and move on to IJKL. This makes the CPA exam easier to pass. 
With the CFA exam, you have to memorize the whole alphabet, A-Z. That’s Level 1. (Level 1 is about as hard as the entire CPA exam.) In Level 2, not only do you have to remember A-Z, you have to learn how to put the letters together to form words. In Level 3, you have to be able to to put the words together to form sentences. 
All this makes the CFA exam MUCH harder than the CPA exam.

To summarize, the CFA exam is probably 4-5x harder than the CPA exam. However, college prepared me for about 90% of the CPA exam. 
Even though I have a Master’s in Finance, it only covered about 70% of Level 1, and less than 30% of Level 2. I have never seen most of the Level 3 material before, so I’m having to teach myself. 
When people say, “The CFA exam is not an ordinary exam,” they are absolutely correct. It is harder than the Series 7, Series 66, Series 63, CPA exam, SAT, and GMAT all put together. (And yes–I have taken all of these exams. I have passed all of them except the SAT and GMAT, because there is no “pass” on them.)