From my experience, I'd be VERY VERY wary of a Certified Pre-Owned anything from verizon. After 10 -yes, that's right, you didn't misread, and I didn't mis-type, I had 10 (ten) (and not base2, or even base8) - CPO Droid 1's. I finally talked Verizon into sending me a CPO Droid2. It just came today, and seems mostly OK. Only time will tell on this one. If you do get a CPO, check EVERYTHING. And I do mean EVERYTHING to make sure it is to your satisfaction. I find that I rarely use the physical keyboard, so a couple of my replacement phones I didn't catch the problem until weeks later, when I'd slide open the keyboard and try to type something. So I learned to check every key on the keyboard, more than once, before even activating the thing. Check the slide mechanism to make sure it's smooth, and detents at full open and full closed (otherwise, it may come open in your pocket/holster). make sure it charges, and can transfer data to a PC (my last D1 would randomly reboot to the bootloader screen when connected to a PC. Not every time, but sometimes. And I primarily charge mine from a PC..so guess what happens when it dumps to bootloader? Yep, no chargey. So I get up in the morning, expecting a fully charged phone, and instead, it's completely dead, despite being connected to my PC all night, and showing charging when I went to bed.
So I would run away screaming from a Verizon CPO phone; but of course, that's just my experience.