A common misconception in determining the value of translations is that it should be compared to another English translation. This is a grave mistake on anyone’s part for it is almost like the blind leading the blind. In order to get an accurate feel for a translation, its validity, and its usefulness, one must first compare it to the original Greek and Hebrew. The primary problem with this is that many people do not know the original language and therefore come to conclusions based on false accusations or misunderstandings about the text and reasons for a certain translation of a phrase or sentence or word. The beginning point in considering the accuracy of an English translation is in its original text—the Hebrew, Greek, and Aramaic—not another English translation.
The second common error I have seen is assumptions that have been made which would be settled after reading the preface of the English version. For example, the preface will tell you whether it leans towards a more literal (word for word) translation, a thought-for-thought translation, or a paraphrase translation. These three types of translations all have their uses and shortcomings. I recommend people have at least one of each for personal, in home study as it helps clarify and check each other. The preface also discusses the original texts used and which ones will be used in case of uncertainty. The preface is a very useful tool to the student of the bible (which I know you already realize).
The main point I wanted to get at is one must compare new and old translations with the original language texts in order to fully know the benefits and short comings of each text. But, in the event that an individual does not understand the original languages, the preface gives a little bit of help and insight which proves helpful in understanding why certain wordings have been chosen.
What dangers do you see in using only one translation or making the claim that one is better than another?