Karel, OK1CF was one of my very first DX QSO’s back in 2001, when I got into DXing. I just worked him with an easy 59 each way. That was on the phased vertical array because the end fire NE direction is over the pole. The doublet is aimed SE.
The doublet is now receiving RI1ANO exactly better than the phased vertical array with the same level difference as the OK1CF test – because it is in the right direction. The broadside directions on the DX Engineering DV-40-P just don’t match the end fire. The end fire array and doublet are comparable. The broadside array direction pales in comparison.