If referring to my particular Cosmo, it has never been bent in any situation, nor dropped, knocked, sat on, or even kept in a tight pocket (when carrying it, I keep it in my shirt pocket, inside the Gemini slipcase - as my Cosmo slipcase still hasn't arrived).
IMO, you will be sorely disappointed by the quality and usefulness of the slipcase. In my case, relying on the slipcase caused more damage than it prevented. Once you've slid the phone in and out a few times, the case no longer grips the phone very well. In my case, I pulled the phone (in its case) out of my pocket. Case was upside down in my pocket for some reason. As the case came out of my pocket, the phone slid out and hit the driveway. Now the two back corners are damaged on either side of the hinge.
Personally, I think the case is worthless - a waste of money and yet another layer making the phone awkward to use while on the go.
As far as the phone itself goes, the two biggest issues with using it as a daily driver are the randomness of the front screen turning things on or off and making calls at random while in my pocket. Yes, you can screen lock it but that makes using the phone even more awkward as you are now unlocking it on the front screen (with its terrible responsiveness) AND the main screen if you have to use it. Why does unlocking the front screen not unlock the main screen?
The second usability issue has been that with each update since v19, the phone becomes more and more unstable. I now have regular multiple reboots per day, alarms don't go off and the phone sometimes doesn't ring when a call comes in. And with each reboot, I have to go into settings and turn the keyboard backlight on which now also sometimes doesn't turn on even after you set it to turn the backlight on (if you go back into the Cosmo settings the backlight magically comes on without touching the slider as if it suddenly remembers, "Oh yeah, I'm supposed to have the backlight on aren't I? Thanks for reminding me!"
The Cover Display and the main phone also seem to be very poorly integrated. It is obvious when you use the CODI that it is its own computer and that it doesn't really want to talk to the main phone. You essentially get two computers to deal with (and update) on one phone that don't really seem to like each other very much. That makes for great seemless usability.
And then there's Ledison. Why it is even installed on the Cosmo baffles me. It does nothing and yet there's even a setting in the Cosmo settings for it. Go ahead, turn it on and watch it do nothing.
After six months of using the Cosmo, I've also cooled toward the keyboard which was originally the big draw for me. Some keys seem to be unresponsive and others too responsive producing multiple presses. It's like there is one perfect tap at one perfect force that makes the key work correctly and if you fall outside of that parameter, who knows what you'll get. At this point, it's not much better than an on-screen keyboard for all the typos that need to be corrected.