I'd have to say B all the way, I am no perfectionist as the A almost implies...But I am a dedicated lover of the hobby. One things for sure, it does not seem to matter how well we have versed ourselves in this hobby, we all still seem to loose fish from time to time for whatever reason...lol
B.. But in careing about my fish I won't do anything blatently reckless or stupid.. and if something does go off kilter i test my water and do what needs doing. But I wouldn't be able to keep as many tanks as I do if I was a Type A person... It'd be more like a science lab then the natural type set-ups they are, which for me would be no fun.
and putting a big tank on an uncertain floor is just reckless...
Tests water parameters regularly during the first few monthes to estimate how much nitrate raise. Once I know how fast nitrate raise per week, I no longer test the water and goes by gut-feelings.
Sets up big tanks wherever I feel like it and just hope for the best. Any first sign of problems, I'll consults a structural engineer.
I memorized the current scientific name of every fish I own (isn't hard since I only keep bichirs, I meant polypterus ).
I researches the efficiency of important equipment thoroughly before purchase. Once I got all the "core" equipments running (etc sump pump, heater). Then I'll buy the less important equipment like lights, wavemakers based on what I like.
Both. A during planning, design and setup of any new system. I'm a research freak. I love the design and build process. Once it's up and running I turn back into a B.
I test fairly regularly, but I'm horrible with scientific names. Not sure why, but I've always used common names.