Wow, I cannot believe people actually use DX contacts as a measure of any antenna's performance... conditions people, conditions, they vary every second. Don't be a r-tard and think that your antenna is no good because one day when you talked to Station X he said you were 9-20 and the next day you were 5-9... LMAO, unbelieveable.
I have used A99, Imax 2000, and Maco V5/8. All work well. Longest lasting antenna is the Maco, hand's down, it's alluminum, best talking antenna...... No way to tell, conditions change constantly, even for local talking..... However if I had to "guess" I would say the Imax 2000 out talks the Maco V5/8 and the A99 is behind there somewhere.... I currently use the Imax2000 with the GPK and at 30 feet above ground (to the feedpoint) it works great, I have no problem making any contacts, on 11M or 10M. My only complaint is that is sways like a wet noodle in the wind and I know it's just a matter of time before it comes slamming down to the ground in pieces... When it does, will likely put a Maco V5/8 back up in it's place, BUT may just buy another Imax and start over the waiting for it to break process again!