disapointed with bowties SS HELP

In an earlier thread I mentioned I was going to stack two 8 bay antennas properly and did. I increased a few signals minisculy to some stations about 100 mi. north of here but really did no good at all with what I was trying to get south of me at about 60-70 miles. All in the flat. (yes I have a rotor) They were amplified by the 29db UHF Winegard amp. I was not happy with the minimal results. As two of the stations supposed to be "local" PBS and another is a local independent that does live shows which I have guested on. So I gotta get them more often than just on 80 degree nights!

So here's my question Solid Signal, This is important to me. I will be glad to try a double stacked HDB91x or Antennas Direct HG91 or whatever it's called. To replace the 16 bay amplified array on my roof if you think it will significantly improve it. Also recommend another amplifier if so needed. I am also going to use a new thicker short run as poss. coax. I know the Winegard HD8200 still supposed to beat these units by 3 db on UHF one of your salesman told me but I beg to differ. My first 8 bay from ANtennas Direct out performed it. I still have the 8200 up on another pole. It's a master at VHF and FM but UHF no. ANy suggestions?, or leave the bowties? Try another amp? I don't know but I only wanta make one more trip up that ladder.