First my credentials: I have a Master Degree in history and have studied ancient Rome for decades, including primary sources.
Cornell has done an amazing job in investigating ancient Rome from the Bronze Age to the Punic Wars. However, and this is a BIG HOWEVER, the book was written in 1995, and enormous strides have been made since then. For example, Cornell states that the first settlements of Rome were small groups of people in scattered huts in 1,000 BCE. Recent archeological investigations have shown that modern humans lived in the area at least 100,000 years ago, and maybe as long ago as 200,000 years. In addition, small settlements were in place more than 5,000 years ago. Of course, Cornell could not have known this.
Also, it is now much more common for ancient historians, archeologists, etc. to incorporate experts in geochemistry, climatology, dendrochronology, chemistry, physics, astronomy, DNA analysis, and many more disciplines in their research into ancient peoples. Incorporation of these diverse disciplines has added enormous amounts of information to the investigation into pre-history.
As a result, I cannot recommend this book to anyone who is not very familiar with the latest findings. Anyone not familiar with them will be misled by the data in the book. There is valuable information in Cornell's book; however, only someone conversant with the latest findings will be able to pick out the valid data from the outdated.