Yes, polyester-spandex blends are an excellent choice for road cycling and hot-weather riding. The polyester component is outstanding at pulling sweat away from your skin and drying quickly, which keeps you cooler and more comfortable on long rides in the heat. These fabrics are also lighter than nylon-based alternatives, so they feel less bulky and more breathable.
The trade-off is durability—polyester-spandex isn't quite as tough as nylon-spandex and can develop pilling over time, especially with frequent washing. If you're riding trails where shorts might brush against branches or saddle edges, nylon may hold up better.
For road riders logging miles in summer, though, the moisture management and lightweight feel are hard to beat. Just make sure the blend includes at least 15-20% spandex (also called elastane) so the shorts maintain their shape and stay put while you pedal.