I too played with the JACk and BATWING and although the JACK may have out done the BATWING is a few instances the larger size of the BATWING always trumped the JACK.
The JACK really had to be pointed precisely towards the transmitting antenna. The BATWING was more forgiving with its slightly bigger beamwidth...
The best antenna I played with was the Antenna Direct DB8 BOW-TIE antenna. This is what I use today here at the house. It was not a good usable antenna with my RV setup due to its mounting requirements...
If you need to increase the BEAMWIDTH of this type antenna this BOW-TIE setup with the two banks adjustable really works great as well... This allows you to zero in on two different locations from the same same town.
Roy Ken