Don't mix up nRF24L01 and nRF24L01+. nRF24L01 is obsolete.

There are chips/boards called RFM70/73/75. 70 and 73 are not fully compatible to the nRF24L01+. They offer some enhancements if programmed correctly. RFM75 is brandnew and could be compatible. Not tested yet.
SI24R1 is a very new clone from Taiwan. I found it fully compatible. It offers some enhancements if programmed correctly.
Most boards on Aliexpress carry the SI24R1 as of today.
Anarduino sells the RFM stuff.