Some people love flip phones, some people hate them.
Having had both basic phone styles, I definitely prefer the flip style.
I have a LG-TM510, and aside from a terrible interface, it's a great phone, with good sound quality at both ends, and substantial feeling, high quality construction. It was the saver's alternative to the Motorola V60c, which was still nearly $400 when I purchased my phone for $150.
People have complained about this phone's battery life, but their complaints are without merit. I've found that it has excellent battery life, but the state of charge indicator is just calibrated differently from some other phones. When the battery warning goes off and the indicator starts flashing, you've still got a good 20-30 minutes of digital talk time, and I can't even guess how much standby time. The results of my 3 tests with a 4 month old standard LG battery are 117 minutes analog talk time, 233 minutes 800 MHz digital talk time, and 237 minutes 1900 MHz digital talk time. Actual talk time "in the field" will obviously be less, due to standby time and backlight usage. My test just shows the theoretical maximum connect time, from the time it is taken off the charger to the time that the phone shuts down due to a low battery.