The short version: Not worth it.
The long version: Smith built the interstellar adventure story about as well as anyone of his generation; arguably, he originated it. But "of his generation" means a lot of things: cardboard characters, unlikely coincidences, and an appreciation for science precisely as far as, and no further than, it served the story. (I remember howling with laughter at the excuse for FTL travel by simple acceleration in _The Skylark of Space_: "After all, E=mc² is just a theory!")
So this one is about two women and two men who build an experimental starship and get lost in space. They have a lot of adventures and eventually find their way back home. Eventually they pair off and marry.
At that level, it's a retelling of the first Skylark book, only without Blackie DuQuense, In fact, there are no "bad guys" in this book (though there is an obnoxious bureaucrat). The women are much more competent in this book than in the other series,which is a plus.
So: in an indeterminate future, apparently ruled by corporations, an independent group called the Galaxian society builds - with grants from a corporation - an experimental starship. It is capable of going anywhere in the Universe in the twinkle of a Christmas light, and it's huge, capable of holding (briefly) a hundred people in its main hall. The people who run it must be Operators - psychics - and, in particular, Prime Operators. The Primes of the crew are Dr. Cleander "Clee" Garlock, the physicist whose theories run the ship, and a Dr. "Belle" Bellamy - though what she is a doctor of escaped me. The regular Operators are a woman named Lola Montandon, a sociologist; and James James James the Ninth, the engineer that built the _Pleiades_.
None of these is a character, of course. They are bundles of canned personality traits who are clearly destined to fall in love despite (or because of) early animosity.
Anyway, the only problem with the ship is that there's no know way to steer it. But they try it anyway, and find themselves in some other galaxy too far for them to identify or know the direction home. Hopping galaxies aimlessly, they discover that Earth-style planets are a dime a dozen, and all of them have humans, exactly like Earth's, interbreedable. Further, each of these worlds has "guardians of mankind," sort of sapient four-armed dog-creature,who protect the people of each world from a variety of monsters.
When they learn to steer it - psychically of course! - they head back to the Milky Way and learn two things: first, that there are no guardians of mankind here; and second, that every Earthlike planet has bred exactly one pair of Primes, who are in various stages of building their own starships.
I cease here lest the gentle reader be nauseated.