well, I've had it for 7 months now, and this is my third one; been replaced twice up to this point
LG has this thing locked down tight as a drum, and even with some great dev's working on this, there isn't anything to flash yet. there is some progress on CM11, and MIUI, but without a custom recovery for KitKat, a downgrade to JB is the only way these roms might work, once they get them working.
Its not a bad phone, but not one that I personally want to keep much longer, and I am happy that I am an "old" jump customer on TMO, so I can try something new in a few weeks, and if I dont like that choice, I can switch it out again, without paying anything..
Everybody feels their own way about phones, and for me, this one was a nice novelty in the beginning, but I miss customizing and trying new roms whenever the urge hits. I'm curious what the "new" Flex will be like when it comes out, but I'm pretty sure thats at least another 3 months or more away.