Best red dot for a ACOG

Just got a LWRC A3, spent quite a while and found the ACOG I want. I'd like to have a red dot on top like the doctor or the rmr, but don't know what to go with. Haven't seen any pics with the rmr on top a ACOG or heard anything from anyone that has done that. From what I can see the rmr is larger than the doctor if I'm right.
So basically my question would be, what is the best red dot on top of a ACOG? Looking for a tough durable long lasting red dot. The Doctor looks great, just looks fragile to me though, like if I dropped my gun it would be all over. Does anyone make a mount for those that completly cover the red dot?
Anyways, thanks for any advice!

Hi,

The RMR is a little bigger than the Docter and the TRD Red Dot Sights. As for strength comparison, I am not aware of any official or third party tests that put them all through the mill, but they are all very strong. We are working on getting the mounts for the RMR on a 4x ACOG and we have them for the compact ACOG sights. We have equipped many ACOG sights with the Docter red dot without any known issues. We have no mounts that will completely surround the Docter, but the protective wing mount does a fantastic job.

The TRD is the one most folks go with. It's a bit more resilient than the Docter, which is a superb sight made with Zeiss glass. Both are excellent. The mount will be chosen depending on the model ACOG you have.