[TowerTalk] 40 meter Yagis

[cqtestk4xs at aol.com]

In the process of what to do about 40 meters at my new location and I have a few questions for the group.  I will have one 126 or 136 foot tower (Rohn 55 with Phillystran guys.  Plans are to stack two 2 2-element Yagis.  I've narrowed it down to the Cushcraft XM-240 and the JK mid-tri 40.  Realize they are two different approaches  to the issue but I have lots of different ways to go.  What I am concerned about ...
First, I have spoken to Ken  at JK and he assures me we can get less than 2:1 SWR from 7.0 to 7.2.   The Cushcraft's info says 250kHz for the XM240.  I'm curious as to other's experiences with either antenna as far as structural integrity, band width, performance, any issues etc.  Also wondering if anyone has stacked these and what effect it had on the SWR curve.
Thanks for the help.
Bill K4XS