Because this antenna was manufactured with an apparent expectation that it be mounted for the most performance potential with the tip at the same place as the antenna it is replacing I thought it good to test in that particular position to see whether it delivered.
Whether or not this was because of height restrictions as the AP was designed to deal with is not anything I've read or heard, but I'm not afraid to offer the Merlin that chance to strut its stuff.
Had I tested it at the same feedpoint elevation first many would step up to say the longer antenna was given an unfair advantage. It is a short antenna from the coax connector up. So, I have reversed the argument in favor of the Merlin for now. I think that the advantages will be with the best design no matter what, so I will try it like this, and if the Merlin should emerge on top this way then we can go to same feed point heights.
Under most circumstances I agree that folks just take one antenna down and put another in its place. I have no argument against that. I have been told this:
I disagree (with tip height comparisons) . . . In order for performance comparisons to be technically valid they must be tested to a control, and that long accepted control is feedpoint height above ground. Promoting manufacturers recommended install procedures as being essential in measuring performance is altering the baseline control. In this case effectively changing the control to 'tip height above ground'. Changing the measurement criteria for different antennas gives no valid comparative data, shifting the measurement ball-park is a marketing departments domain. 
This antenna was seemingly made to compete in areas with restrictions on antenna tip height (thanks for the info wa10). This is fair enough, but performance measurements according to their install instructions is only valid in that restricted environment, not globally. And these pivotal points are what I tried to get across in my previous post.
I applaud your efforts constructing and looking at antenna performance from different angles, but without a standard measurement control you must expect contention."
A perfectly legitimate response, and point taken, but I still think that until I answer the questions surrounding this mythological antenna at least for myself there will always be protests against whatever conclusions I come to.
I do believe this antenna is a perfectly good option, but beyond that I have not decided.
