I bought the Dirty Design unit first but I had 3 problems.
1) I live in Southern California where the sun is very bright much of the time so I use the Hoodman sunshade which totally blocks out all light if I so choose. It adds weight to my iPad mini and it tends to twist in the DD holder.
2) The unit is not easy to store so I have to strap it to the side of my GoProfession Cases backpack.
3) The iPad ends up being too close to the antenna with the DD. On a couple of occasions I got a wifi error. I use wifi to hook up to a wifi/4G hotspot so I can use use maps. Haven't had the problem since I switched.
I have to say, though, the best thing about the DD unit
is the lanyard mount. It's perfectly balanced.
If you don't have a heavy sunshade like I do then you probably won't need to mod the controller like I did.
I bought the Mavmount because I wanted something that was more sturdy. It is. The extra weight isn't an issue for me. One problem for me was that the MAVMOUNT has an odd shape so it was hard to stow. Also with the Hoodman attached it tended to bounce a bit in the controller I modded it and the controller and it fixed both problems, plus I added an lanyard mount. Here are some pix:
Took the hardware off.
Found a 1/2" tripod mount screw that fit the base
Moved the ball joint up to the next hole. Screw holds like a champ.
Sawed off a lanyard mount I had used for my racing quad (I have several). I used the original mounting screw from the base and a nut that I had. Holds extremely well but the balance is not perfect, but then nothing is these days.
There was still some play so I rolled some SUGRU into a small tube between my fingers and molded it into the space between the plate and the extra space on the controller.
The fix! When it dries after 24 hours the SUGRU feels exactly like the rubber that DJI uses to grip the phone in the side arms. It's like hard rubber and sticks to anything. You can find it in most hardware stores or online. Comes in lots of colors. I've fixed everything except my cat with the stuff, and she's getting nervous.
I pulled the MAVMOUNT out and let it dry for 24 hours. Looks like stock
Finished product still stands on its own plus I can disassemble it and stow it faster than I ever could with my Dirty Design clamp.