I was very excited when First To The Rhine came out because I thought it was high time someone produced a history of 6th Army Group. While reading the book, I was a little disturbed at the number of small factual mistakes made by the authors, and the more I read the more disturbed I became.
What really set me off was the intentional misrepresentation of Eisenhower's standing orders to his army groups in the fall of 1944. In their discussion of Eisenhower's decision not to allow 6th Army Group to cross the Rhine in early December 1944 the authors represented his standing orders as not including a specific mandate to secure a bridgehead across the Rhine. Instead they reworded the orders to something like seizing bridgeheads across rivers. This allowed them to circumvent the difficult and complex issue of Eisenhower's error in not allowing 6th Army Group to cross the Rhine when it had the opportunity.
As I have some of the same primary sources used by the authors, I went back and began the laborious task of checking their citations, and discovered that a good many were simply wrong. The source either did not say what the authors claimed, or said something fundamentally different such as the wrong unit, the wrong day, the wrong order of events, etc. Taken in toto these errors represent fatal flaws and render the book far less useful than it otherwise might have been. It is the product of sloppy research, and I cannot recommend it.
While not perfect, Colley's Decision At Strasbourg is a far more reliable examination of Eisenhower's fateful decision not to allow 6th Army Group to cross the Rhine in December 1944.