It seems that JetPack is committed to being the only plugin you may need for almost any WordPress installation, and today you have introduced a new module, in version 2.9, that all or almost all of us use, the related entries .
And the truth is that it is very complete, more than many plugins out there, these are its virtues:
What's up, it works relatively well personally I prefer Related Posts by Zemanta because it allows to customize the appearance and edit the related entries and it's faster, but you have to recognize that the module Related entries of JetPack is fast to load and minimalist in appearance, which will fit most designs .
The main drawback, logically, is the absence of customization possibilities and improvements in the selection of related entries , because it is not always correct with the most related. In any case I encourage you to try it, bad option is not.