I have both. I got the Flex for $109 and the much larger Max for $380. Sure the Max is louder, has more bass, better Bluetooth and an AUX input. But the Flex has it's own features and less annoyances that it's hard to accept the much higher price of the Max.

Here is why the Flex is better:

1. The Soundlink Flex has a microphone. The Soundlink Max does not.

2. The Soundlink Flex can be turned on from your phone! When I'm in bed, I can turn on the speaker from a distance using just my phone. For the Flex, I go to the Bose Connect app and slide down the icon to turn the speaker on. However the regular Bose app of the Soundlink Max does not allow this. I must manually press the power button on the Soundlink Max to turn it on.

3. The Soundlink Flex has no white noise. On the Flex, there is white noise after pausing music but it disappears after 5 seconds and the speaker is completely silent. But for the Soundlink Max, after you pause music, white noise remains indefinitely, and it is noticeably loud when your room is super quiet and your ears are near the speaker. For those who don't know, white noise is the background noise the speaker makes when the speaker is on but not playing sound. It can be annoying for some people.

4. The Soundlink Flex has accurate battery readings. The Flex has an accurate battery update at all times. But for some reason, the Soundlink Max has a delayed battery reading. I can play music for hours and the battery level on the Max remains at 100% from day to night, giving me a false impression that the battery is that good. But the next day, when I turn the Soundlink Max back on, that is when the battery reading adjusts itself and the 100% battery from the previous night suddenly drops down to like 60% in the morning.

Why aren't people who own both speakers pointing these things out?