Over the last few days, my approach to monitoring a mix has completely changed. I love the fact that it's fairly cheap, flexible and able to easily travel.
First, I begin the mixing process on the JBL Series 3 speakers (either in stereo or 5.1.4).
Then, I check the mix against my Bose SoundLink Bluetooth portable speaker. So far the JBL's translate to the Bose REALLY well.
Once I'm fairly happy with the mix, I can move over to the Monolyth M1060 planar headphones (again, in either stereo or 5.1.4 - thanks to DearVR Monitor with the LCD2 headphone emulation switched on and a bit of high-end EQ in the monitoring chain added). This is where you can hear the extreme depth in the bass and overall mix. At this point, I tend to trust the JBL and Bose speakers for levels ... however, so far, there isn't much difference. The mix tends to translate across all three monitor setups REALLY well.