My prime favorite OLED aspects have been

• better battery life
• Noticably quieter fan
• Significantly improved thermal efficiency oled runs 10-15 degrees cooler than lcd at similar settings this was my main reasoning for wanting the oled
• Noticably lighter weight feels good
• matte shell making steam deck oled easier to grip than the lcd version
• thumbstick grips significantly better than lcd no need for thumb caps
• much more responsive and smoother UI
• oled screen actually took me by surprise colors aren’t as washed out as lcd also the screen itself feels harder than lcd
• The track pads ! Wow way better accuracy and haptic response and theyre not nearly as ultra sensitive as the lcd track pads
• Can play games at at higher fps depending in the game and settings
• A lot less frame hitching

I find the oled to be a very worthwhile upgrade and have zero regrets getting it overall super pleased with it