Is it just about weight or do more things come into play?
Other things do come into play, aerodynamics, stiffness, comfort, strength, but weight is a major factor as rotating mass counts for more than static mass.
As with many things bike-wise it depends what you are looking for in 'better'.
Acceleration or climbing requires a combination of light weight and wheel stiffness but this may be at the expense of comfort.
Aerodynamics might be at the expense of weight, thus a deep section aero wheel would not be beneficial if you live in a very hilly area, but maybe great over flatlands and long straight roads.
You might be happy to sacrifice acceleration for comfort for long distances.
Talking to a good wheelbuilder is a start rather than just going on reviews. They have a lot of experience and will take your weight and usage into account.
Harry Roland
DCR Wheels
Pete Mathews
... and many more ....
Then you get to choose rim, spoke and hubs to suit, the prices are usually competitive and hand-builts are very repairable.