Here are two screen shots I just took to better explain the differences I've seen and also the problems I've encounterd. Both views are unmagnified.
The first one is from AH2. I went down one side of the feild and destoyed the ack. Went back up to 6k and this is what I saw.

You, cannot tell the difference between an ack that is down or one that is up. Zoomed in or not.
Now, here is one I just took from AH1. I did the same thing here. Went down one side of the feild, destoyed the ack and left the other side up for comparison. Climbed back up to 6k and here is what I saw.

Even zoomed in on the ack in AH2 from that alt, there was no way to determine which of the acks was up or which was down.
NOW, like eagl said, maybe HTC has some reason for making the ack tougher to see. I dont know. But the fact still remains that there is a clear difference between AH1 and AH2. IMHO I think its a problem. Not because its more difficult to see, but because it just cannot be seen.
Maybe this change was intentional. Maybe not. If it was intentional, then why? I just want to know.Thats all.
But regardless of being able to see if ack is up or down from 6k, the fact still remains, that when sliders are set to say, mid way, ack that is up cannot be seen until you are right on top of it... Literaly.