I've tried two cases for the Droid Maxx. There aren't a lot of options out there, but there are some pretty good ones.
I originally bought a Diztronic TPU case, mostly because the price was right (<$10). As an advantage, it was very, very thin. Thanks to the form factor, the phone still fit in the clamp-style car mounts I had, and played nicely with wireless chargers. But the thickness, I'm sure, limited the protection it offered. Still, I dropped by phone on concrete from waist height a couple times with no visible damage. My biggest annoyance with the case was that it didn't seem to play nice with my Skinomi screen protector. The screen protection has a lip that extends over the front of the phone about a millimeter. Because the case is fairly flexible, hitting the power of volume buttons would sometimes warp the case, and peel back the screen protector.
Next I tried the Incipio Dual Pro case. This case is slightly thicker, although so far I haven't noticed the (slightly) added bulk being a problem with any of my other accessories. It still fits in the mounts, and wireless charging still works. While I haven't done any tests to confirm this, I strongly suspect this case offers a fair bit more protection than the Diztronic case. This case has a bit more structure to it. There's not much of a lip that extends over the front of the phone- instead the plastic shell seems to hold the silicone core in place. So, this case doesn't seem to have any problems with screen protectors.
Both cases have their advantages and disadvantages, but personally, I like the Incipio Dual Pro better. I would have gotten it originally, but I expected it would be thicker. The Diztronic is a good ultra-thin case for those of you who don't need a lot of protection, but keep in mind the problem with screen protectors. If you use on of Zagg's smaller "case-friendly" screen protectors you'd probably be fine, but I prefer the Skinomi ones.