I haven't used Bit defender before and the user interface doesn't seem anything exceptional. Although the functionality is the key and for that I feel its alright.

I also have no idea if 97% is a good detection ratio or not. Of course I do not have a previous experiences of testing an antivirus so I am going to take you word for it. But the files getting randomly deleted by a malware that remained previously undetected makes me loose some confidence in it.