Cardioid microphone patterns have excellent sound quality features. They are very sensitive to sound and enhance the sound quality and tone at the same time. Their pattern is such that a speaker into microphone feels very good to hear their own voice, which gives an added confidence and makes the speech an effective hearing for the audience.
Cardioid microphones are often used for speech delivery or talk shows. Also, they are used by singers, especially in noisy areas, where their voice without these microphones' help is difficult to reach to the target audience in much clarity. Their use is particularly effective in mass gatherings where thousands of people are present to listen to the speaker.
Cardioid microphones have an inbuilt noise filtering feature, which prevents unwanted voices and noise to mix with the speaker's sound. This is the reason that these microphones are commonly used in open places, where there is air noise, crowd's noise or even traffic noise. At mass gatherings where too many people can be presented near the speaker or singer, these microphones become very useful tools in helping the speaker to reach their audience in clear words.
Cardioid microphones come in different dimensions but are not much different in function and quality to each other. There can be a slight difference in shape of the microphone but obviously nothing is compromised on the quality and features of the microphones. Nowadays, some copy versions of these microphones are being thrown into the market by some low-cost manufacturers, and there can be some complaints in their sound quality if you prefer them over the original versions.
It is always better to select branded and quality products, especially if you are using the microphones in delivering speeches or lecturers to a wide audience. Compromising on the quality can embarrass you in front of your audience.