One simple point here: a translation can serve as a tutor. Some think of a diglot as a “cheater’s text,” but it doesn’t have to be that way. Especially when you are trying to work through a text that is beyond your current reading level, you can use a diglot and genuinely learn from the translation on the facing page. If you use that translation well, it can be similar to the experience of working through a text in a classroom setting. In a seminar, or if you are reading at a coffee shop with a friend, when someone gets stuck, another person chimes in with help, pointing out how to understand the syntax or idiom. The translation can do the same thing if used as a tutor.
The key to using a translation well is to look back at the Greek once the translation has been consulted and figure out how the translator got from point A to point B. The process might go like this: The translator says “at his expense.” Where did that come from? Is it ἰδίᾳ? OK, so that is a meaning I’ve never considered. You could at this point consult a lexicon or just use the context of the passage to see if the translation makes sense. You think about the base gloss you learned for ἴδιος, “one’s own,” and you realize that in this context “at his own expense” makes perfect sense. In just a few seconds you’ve learned from a translation the kind of thing that you might learn from an instructor or reading partner.
Using a diglot — perhaps in conjunction with a digital lexicon — is a way of reading you should consider. It can help you become comfortable reading Greek texts that are beyond your current reading level. The whole idea of “cheating” at reading ancient languages is something that should be left behind. Sure, some ways of reading are better than others for memory, but limiting yourself to only reading when you can do it “the best, most thorough way” shortchanges yourself. You cannot read as many texts that way, and I think reading as much Greek as possible is better than digging through every detail of a handful of texts. So dust off those Loebs and enjoy them guilt free, my friends.