Readings Classics vs Penguin Classics — What’s the Difference?

Hi everyone! I’m getting into classic literature and had a question. While checking the Readings website, I noticed that many classics are available in two paperback options: Readings Classics and Penguin Classics, and there’s a noticeable price difference.

I wanted to ask if there’s any difference in the actual text. Are both editions unabridged, or is one shortened? Are there differences in translation, editing, introductions, or footnotes? Has anyone read the same classic from both editions and noticed a real difference while reading?

As someone new to classics, I’d really appreciate your thoughts on whether Penguin Classics are worth the extra cost, or if Readings Classics are just as good for the full, original text.