Robb I did an antenna comparision yesterday with ZL1BI,
I have the IMAX 60" to the feed piint on top of the tower, The fan dipole 20/40/80 meters is at 56' to feed point.
The Imax RS was a 5-3 to Col using 100 watts.
The Fan dipole using the 3rd harmonic on the 40 meter leg was also an RS of 5-3 with the same 100 watts. The dipole is oriented so the major lobe works into EU and S. Pacific.
Verticals, If installed correctly, radiate rather well in all directions.
Try a 40 meter vertical for dx, ground mount it with say around 24 to 36 ground radials.
More times than I care to count the ground mounted vertical had a better RS report than the two element 40 meter yagi.
The yagi was at 70 ft up the tower, the vertical was 8 inches off the ground at the feed point. The vert was the go to antenna for working DX in EU.
A good vert is hard to beat especially on the lower HF bands.