To make comparison easy, let us take the example of B737 and A320, both similar aircrafts with retractable landing gear.
As seen on the photo below, the B737 doesn't have gear doors for the wheels,
but the A320 does
Obviously, Boeing and Airbus made different choices for the same feature and both seem reasonable. Both aircraft models are well accepted by the airlines.
What are the advantages and disadvantages of both designs?
EDIT: I put links to other images where both aircraft are retracting landing gear after take off. The difference is obvious as we can see the landing gear doors operated for the A320 and no doors for the B737's wheel.