I've read a few of Booth Tarkington's works before, and enjoyed them in a casual way. Penrod didn't work as well for me, primarily for two reasons - it very much feels like an only mildly successful clone of Tom Sawyer, and it's too full of casual racism to ignore.
Penrod came quite a bit later than Twain's work, and it doesn't have the same complexity and depth - it's a light-hearted look at a troublesome young boy out to have fun. But it draws on many of the same elements - clever, charismatic boy, unattainable young girl, childhood antics. It was fun, but too reminiscent of Sawyer to work on its own.
Penrod is also hampered by its social attitudes. While now over a century old, it's still not old enough to get away with the casual racism that peppers its pages. While not ill-intended, it's just too pervasive to ignore - for example, when Penrod is "doing something very unusual and rare, something almost never accomplished except by coloured people or by a boy in school on a spring day: he was doing really nothing at all". A little of that could be excused by the timeframe in which the novel was written. I found there was too much to accept, along with a bit of animal cruelty.
These two factors spoiled my enjoyment of the novel. If you're a big fan of Tarkington and somehow haven't read this, you may enjoy it. Otherwise, I recommend a re-read of Tom Sawyer.