As Tavenger said above, it's not usual to charge the battery that often. Unless of course you are constantly playing videos, or you're playing demanding 3D games. If you're a "power user" then pretty much any smartphone will remain out of battery rather quickly.

As for the screen's brightness in sunlight, again, the iPhone 5 has a pretty good screen when it comes down to color reproduction and visibility in sunlight. It's brighter than most Super AMOLEDs used by Samsung. Of course, the panel is smaller and the resolution is lower, but that's beside the point.

It sounds like you may have some hardware/ software issues with your iPhone 5. Either that, or you need to lower your expectations from pretty much any smartphone . All of them have screen issues in direct sunlight, all of them get hot when recharging (especially if you're using them while recharging!), and most of them don't offer more than a day of battery life, on normal usage.

It's strange that you have to charge the battery 3 times a day. Batteries on iPhones are usually pretty good. Do you use it a whole lot? If not, then there is a problem and I would take it to an Apple store to get it fixed. If you do use it a lot then a Samsung Galaxy phone probably isn't going to fix the battery issues you are having, but it will fix the others. What specific Galaxy phone are you referring to?

I currently have iPhone 5. I am satisfied but it is lacking certain features such as increasing memory by using a mini SD Card, and it won't download many Google features or Mozilla Firefox. Many videos are unable to play (Windows Player). The screen gets washed-out in sunlight (need OLED screen), the battery must get charged 3X day and cannot be changed, the screen size is quite small and the unit gets very hot while charging. I was considering a Samsung Galaxy but 2 friends have battery problems with that as well. I am confused. Any suggestions?