I don't think this does add a compass or at least I couldn't see a mention of it. I think the difference is that it brings it up to the same level as the HERE gps and they added the two extra holes so it fits into the solo better (the previous MRO only had two screw holes as far as I remember).
I did get three of the previous revision MRO's and found them to be waaaaaaay better than the Rev A board that was on my solo (I bought 2 more solo's, hence the MRO upgrade). Then again fixing a map in front of the solo's camera would be a better GPS alternative than the Rev A board.
I then went and bought a HERE system to see if it was better than the MRO. The results were.... maybe.... Look at it this way, I did an indoor test of the sats and hdop and across the board, the results were pretty much the same. In fact one of the MRO 's actually got a better signal than the HERE system, then again, one of the MRO 's couldn't get a lock at all (remember, this was indoors, on a rainy cloudy day, in a house that's on the side of a hill surrounded by tall thick tree's... can't even get a tv signal here). Point being, I did this lame ass test in the worst conditions possible and still managed to get a pre arm sat lock on all but one drone (all tested at the same time, same location, 3 MRO's and 1 HERE). As soon as it stops raining in the PNW I'll do an outdoor test (ie next May).
I like the HERE because it looks awesome, it moves the GPS up and away from the body and it's got a compass installed, so you can retire the compass from the leg too, so no more "magnetic interference" messages when taking off from that big pile of scrap iron..... or so my theory goes...
