I've added several of Erle Stanley Gardner's Perry Mason books to my shelves over the decades. For my first reading any of them, I ended up with a triple dose.
This volume has one novel each from the 1930s, 40s, and 50s. All three are rock solid, fun mysteries. The chapters are exactly the right length for enjoyable reading. Gardner's writing is clean, smooth, and fun.
There are some dated throwbacks like how clue is spelled klew (Agatha Christie did that for a while too) and how curb was spelled kerb.
Despite being from an age before TV, before cell phones, before the Internet, and for a few even pretty much before the golden age of radio, these books have held up well and are still fun for modern readers.
Gardner gives a great job of presenting all the clues (or klews) but with enough smoke screen that the endings while logical definitely aren't obvious.
A couple of years ago I finished reading every Agatha Christie book in order (which I don't regret doing though I'm not quite sure how I feel about her writing). I look forward someday to doing the same with many decades of Perry Mason mysteries.