They are not as good, no. Most players though would not see a recognizable difference in performance.

There is a reason why they are called knock offs…

This is a double edged sword. No, they are not as good of quality as the ones made by the larger manufacturers. A "fake" Calloway will not have had the performance testing and Quality Control testing that was performed by Calloway. What these knock-off companies are doing is taking the same general design and slapping them together and fractions of the cost. You will have no guarantee nor warranty from knock-off clubs, but you will have saved substantial money. There is no guarantee that the fake club you are buying is even built right (shafts inserted all the way, glued wrong, faces not symmetrical, etc…). You may however get a great performing club that is just as good as the more expensive legit versions.

In my opinion, if you are looking to save money and get quality at the same time, get a used set. The first time you use the knock-off it's going to be "used" and become dirty and scratched like a normal used set does. So why not spend the money on a set of legitimate clubs that may have a few scratches, but has also had quality testing done on them to make sure they perform the way they should?

Stay away from those types. There are clone companies, like Hireko, GigaGolf and Pinemeadow, that make legal clones of Callaways with the same steel that Callaway uses. On top of that, you can customize shaft type and flex, length, lie angles and what type/size of grip you want (with an upcharge).

With those unknown knockoffs, they could be made of a softer and unreliable metal. Stay away from those types.

The major thing is that the "clone" clubs are made to look like the real ones. Not to perform like them. Although the knockoffs have that X in the back of the club, It does not feature the same technology that is Callaway's Hyperbolic Face Technology. Yes, the X on the back of the Callaway irons does have a purpose and is not just there for show. Here's a link that will tell you more about it:
http://www.callawaygolf.com/Global/en-US…

Get the real thing. It will be much better than some p.o.s. knockoffs.