These mice are close competitors in the mid-range ergonomic space for medium to large hands. It's actually a very close race.
Both mouse shapes are very popular with ardent fans on each side. I'd say the EC1 with it's weight and cable is more specifically geared towards high performance FPS games like Rainbow Six Siege and CS:GO.
The G502 is more of an all arounder with a ton buttons, better suited for games like Fortnite with a bunch of commands.
If you don't need all the buttons or the weight I'd say you should go with the EC1 for performance benefits.
Side-by-Side Comparison
| Mouse name | Logitech G502 | Zowie EC1 |
|---|---|---|
| Picture |  read reviewCheck Price on Amazon |  read reviewCheck Price on Amazon |
| Length | 13.2cm | 12.8cm |
| Width | 7.5cm | 6.4cm |
| Height | 4.0cm | 4.3cm |
| Weight | 121g | 97g |
| Buttons | Primary left and right click Middle click 2 side thumb buttons Scroll tilt left and right DPI up and down Sniper toggle button Profile switch button | 2 Primary Buttons 1 Middle Scroll Button 1 DPI Button 2 Side buttons |
| Sensor | Pixart PMW3360 | Pixart PMW3360 |
| Shape | Ergonomic | Ergonomic |
| Cable/Wireless | Braided | Soft rubber cable |
| Battery Life | N/A | N/A |
| Software | Logitech Gaming Software: Surface tuning RGB lighting settings DPI stepping Saved profiles on the mouse Button remapping Input analysis Macro recording | No software: DPI settings are preprogrammed Step 1: 400 DPI Step 2: 800 DPI Step 3: 1600 DPI Step 4: 3200 DPI |
| Warranty | 2 year warranty | Unknown length |
| Pros | Lots of buttons to use for mapping in games Great infinite scroll Solid shape | Comfortable super popular shape Flexible rubber cord Flawless sensor |
| Cons | Heavy Cable is still on the stiff side | Loud scroll wheel Issues with accidental clicks |