[Motorola Droid 4] Septfox:
[MENTION=309785]u.b.o.o.t[/MENTION], don't count me out just yet... still have the phone after all, haven't even cleaned it out. I'd be interested in messing with whatever tweaks you make, only thing I can't do now is cellular-related stuff since my service has been transferred.

I was going to PM you all this, but I'll put it here in a spoiler for anyone else considering the same purchase.

I bought mine on eBay, but it was posted on Swappa as well. I'd keep an eye on both, aim for $160-$180 for one in good/excellent condition with no accessories aside from the retail stuff (charger, box). Most sellers will probably entertain offers too, as long as you don't lowball it.

Mine cost me $185 ($175+$10 shipping, was $195+$10 but I made an offer $20 lower via eBay): practically mint condition aside from some dust in the speaker grille, came with two good ~$9 cases (Diztronic and Speck Candyshell) and a Verizon tempered-glass screen protector. I think I got a good deal, 100% satisfied with my purchase so far.

Try to get one with an undamaged screen (bonus if you can get one with a Verizon-installed protector, no errant pre-application dust or scratches to worry about), it looks like replacing the digitizer is a pain due to all the glue stuck to the glue that's holding the glue in place to properly stabilize the glue. Once it's scratched you'll probably have to live with it.

If a decent case doesn't come with yours, shop for one that protrudes some out front past the screen; unlike the Droid 4, there's no raised-bezel screen surround to protect it, landing on anything hard face-first will almost certainly wreck the digitizer. The phone as a whole feels sturdy, however. If it weren't for the screen glass being so exposed, I would probably feel almost safe going without a case.

Make sure you get the 64gb model: the Quark (Maxx/Turbo codename) has no SD card slot, so once storage is full that's it. If you're wanting to get one of the metalized-fiber-backed versions, I believe they're only available in 32gb; you can buy a replacement back on ebay for something like $14 and pop it onto your 64gb version, since the models are physically identical otherwise (as far as I know). They use different-sized 3rd-party cases, though, so make sure to get a case to fit your final product; the metalized-fiber back isn't as thick and probably won't fit snugly into a case for the ballistic-nylon version.

Also fyi, there's no functional difference in the Limited/Employee-Edition models, they're just 64gb ballistic-nylon-backed phones with (admittedly nice) special trim and a unique serial number printed on the camera cone. Similarly, the specially colored ones (e.g. Sapphire Blue) are just that...specially colored. Also only available in 32gb, annoyingly.

Software version isn't a concern for now, SU4TL-49 is the latest and is cracked. But if Marshmallow releases while you're shopping - anyone's guess as to whether it's actually in the works, almost done, shelved, whatever...Verizon is being Verizon - you might want to make sure the seller hasn't taken the MM OTA. Chances are very good that Verizon is going to patch the bootloader exploit while they're at it, in which case it'll likely be a while (if ever) before it's cracked again. Once you do have it unlocked though, you're golden and can flash anything you please (even stock images), just don't be dumb and try to relock it; bad things happen, and it's absolutely pointless to anyway.

The unlock itself via SunShine is $25, factor that into your overall expenditures. Even if you plan to run stock, it's worth it to ensure both the ability to run a proper recovery (TWRP) for backups/recovery from oopses/flashing SuperSU/Xposed, and update in the future (CM14+, since VZW probably won't bother with Nougat).

Once you get your hands on the phone, use RSD Lite to flash stock SU4TL-49 properly before unlocking. SunShine rejected mine at first because apparently OTAs don't always completely update the phone, causing it to throw an "incompatible firmware" error.

Speaking of software, if you're planning on running anything that uses Safetynet, avoid Resurrection Remix for the moment unless you know how to "fix" it. Something in it is different enough to fail the CTS Profiling checks every time. Bliss/CM13 and the modified-stock ROMs work fine once root is disabled, though not quite as smoothly as stock in my admittedly-limited experience.

Whew.