I saw an interview with Malwarebytes' creator and he said that you should never have to do more than the quick scan. He said that was all he did himself. They keep the program updated with all the places that malware inserts itself and if they find out about something infecting a new location, they add that to the quick scan. He claimed that he had tested it and never found any more with the full scan over the quick one.
Avatar FX6327X Desktop, AMD FX-6300 6 core CPU, Radeon R9-270X graphics, 8GB RAM, Windows 8.1 64 bit, Bitdefender Free antivirus, MBAM on demand
HP6140 Laptop, AMD A8-3500M Quad Core APU, 6GB RAM, Windows 7 Home Premium 64 SP1, Bitdefender Free, MBAM
Google/Asus Nexus 7 tablet, Qualcomm Snapdragon quad core 1.5ghz, 32GB storage, Android 5.0.2, Dolphin browser, Bitdefender Free All machines behind a NAT router