When you also have the original text, whenever there is a more interesting or obscure paragraph you can look to see what was really said, possibly with the help of a dictionary.
Even when the translation is good, the translator cannot stop at each sentence and explain why certain English words have been chosen, which may be the closest to what was said, or they may be not, but the translator has thought that the chosen translation is easier to understand for an average reader.
The older translations (and perhaps the future translations, taking into account the current trends) also avoided to translate whatever words were considered offensive when the translation was done.
I pretty much guarantee that unless the translation is completely atrocious, what you will gain from this will be even worst. Languages just don't work like that. Trying to fugure out nuance or meaning from word for word dictionary analysis just don't work.
Knowing the letters is enough to allow the use of a dictionary to find most words, i.e. most nouns. Searching for verbs in a dictionary can be more difficult without knowing the grammar, as it may not be obvious which is the dictionary form that corresponds to a verbal form in the text.
I have read many Greek and Latin bilingual books and I have always found the original text to be of great value. The English text is very useful for reading quickly in order to have a general idea about the content of the original text and for searching quickly things in which you are interested.
Whenever you want to know anything certain about the content of the original text, the only way is to look at the original language. It does not matter if the original text looks like the original inscriptions. The original text may be shown in a one-to-one transliteration into Latin letters, without losing any information.
On the other hand, I have never seen any reliable English translation, i.e. any translation where after seeing twice the same English word in the translation you may conclude that the Greek author used the same word in both cases or that the author meant the same thing in both places.
Moreover, almost all translations that I have seen contain some anachronisms, i.e. modern words which do not really have any exact correspondent in the ancient languages, so when looking at the original you can see that the Greek or Latin words actually meant something else. Because of this, I have seen papers in which wrong conclusions were affirmed about what some ancient authors have said, due to the fact that some translations were accepted as being true literally, without checking the original words.
For some of the ancient texts there are editions with commentaries, which include both the original text and an approximate translation for it and in which most of the less usual words and phrases are discussed in detail, to establish their most probable meaning.
While such a commented edition may be the best tool, what they add over a bilingual edition and a dictionary is much less than the difference between the latter and an English-only edition.
The English translations may be more acceptable for literary fiction (where for many people it matters more to be entertained than to know what the ancient author truly said), but they are particularly bad for any text that has any scientific value, e.g. Aristotle, Plato, Pliny, Herodotus and so on, because the translator normally lacks expertise in sciences and is unable to identify the appropriate English words.
Even in Homer, there are many names of animals, plants and minerals, or even of colors, which are normally mistranslated into English.
I think, if you've studied classics, you should know that seeing a few greek letters in a mathematical formula and mispronounced is nowhere near being able to parse a word written in Greek letters.
> I have read many Greek and Latin bilingual books and I have always found the original text to be of great value.
You've misunderstood, though. The latter is true because of the former. The comment I replied to specifically referred to people who don't know the language.
> The original text may be shown in a one-to-one transliteration into Latin letters, without losing any information
Not exactly true because our alphabet doesn't have standardized stress marks, aspiration marks, or even standardized 1:1 transliterations of the characters. But in general I think you're correct that transliterating it could be helpful.
> On the other hand, I have never seen any reliable English translation, i.e. any translation where after seeing twice the same English word in the translation you may conclude that the Greek author used the same word in both cases or that the author meant the same thing in both places.
I am pretty sure I have, but I don't have any references on hand.
> Because of this, I have seen papers in which wrong conclusions were affirmed about what some ancient authors have said, due to the fact that some translations were accepted as being true literally, without checking the original words.
You've definitely hit an important point here. Even without having studied classics very intensely, I can almost immediately spot bullshit peddlers when they reference "the Greeks" and quote some passage completely out of context. But most of the time, it's less about the translator's word choice and more about ignorance of the society in which the original was written. That's not something you're going to get anyway from laying the original text next to the translation.
None of that is science in contemporary sense.