Vertical vs horizontal elements, it depends on the height. If you have supports high enough to suspend a 40 meter LP vertically the horizontal configuration (comfirmed using EZNEC) will perform better at all take-off-angles. Ground loss in the far field reduces the performance of the vertically polarized LP.
Thanks for that info. My intention is to extend the length somewhat and make it cover 7, 10 and 14 Mhz. Have been working through some options using the calculator by KM9O. So might try one with 13 elements and a "boom" length of 157 feet.