I've got this book. It does tend to present a rather conservative view of textual criticism and they are on the optimistic end of the spectrum in terms of the stability and faithfulness of the early transmission of the NT.
The other end of the spectrum is Brat Ehrman who argues that the text of the NT was corrupted at a very early stage before the text is well attested in the manuscript tradition.
But my favourite scholar on textual criticism is David Parker who is one of those who argue now that it is misguided to view the "original" text of the NT as the ultimate goal of textual scholarship. Instead he argues that texts are always fluid and their dynamism should be explored rather than tamed by dubious static notions of originality and corruption.
https://www.amazon.co.uk/Living-Text-Gospels-Parker/dp/0521599512/
https://www.amazon.co.uk/Introduction-Testament-Manuscripts-their-Texts-x/dp/0521719895/