Looking for recommendations! Should I buy Avast?

Hello Tina.
Thank you for reaching us here.
Please visit https://www.avast.com/en-us/store#mac to know in detail about Avast AntiVirus for Mac platform. 
And yes, you are right about using one antivirus simultaneously. It is generally not recommended to use more than one security solution on a single system. They will compete for resources, which may result in slowdowns, crashes or in no protection at all.

Regarding Bitdefender and Norton, we cannot comment on performance and reviews of a 3rd party antivirus software. 

Hello Tina.
Thank you for reaching us here.
Please visit https://www.avast.com/en-us/store#mac to know in detail about Avast AntiVirus for Mac platform. 
And yes, you are right about using one antivirus simultaneously. It is generally not recommended to use more than one security solution on a single system. They will compete for resources, which may result in slowdowns, crashes or in no protection at all.

Regarding Bitdefender and Norton, we cannot comment on performance and reviews of a 3rd party antivirus software. 

Hi Everyone, I have been trying to switch to another antivirus for my Mac lately. I use Bitdefender and it's not that fast, to be honest. I checked out various comparisons and independent lab tests (check out reference here) to evaluate which antivirus would be better to go for. I am having a dilemma between Bitdefender, Avast and Norton. Avast has great reviews. Also, let me know if I should uninstall previous software or run it along side new one. I personally think using one antivirus is better at a time. What do you suggest? Please. Please, let me know. Thanks!!