Hello Jessie, and welcome to VT!
Popular? Why just the selection between those two? To me, neither are overly appealing, but the choice you make will be based on price, functions, size/feel, button-placement, and features (floating/adjustable pin, materials, color, etc.).
You'll find that many of us here may agree that a particular device may suit the needs of the masses, but we also agree there is no "popular" or "must-have" device that everyone should own. What you should use, is based on your preferences and needs... not necessarily what is popular
Also, I'll add... the battery you use in the device is very important... safety first! There are lots of recent threads with the pros and cons of different batteries and suggestions for some of the current, best-on-the-market 18650's