I live within 1 1/2 miles of the tower, but west. Down in a bunker of concrete and steel construction, I had multipath problems with several inside antennas, although I never tried the double bowtie or Silver Sensor. I tried the 'stripped RG6' antenna, which was an idea posted somewhere here. Just strip the last 6-8" of insulation off, I taped it to a 4' speaker stand. It worked and seemed to provide a more stable signal. Next, I found an old UHF loop (the kind you attach to the back of the set with 2 screw terminals). I used a 300/75 ohm transformer and a male F connector to attach it to a cable. It was better than the stripped wire and pretty stable (signals not jumping around).
Might be worth a shot before you try something expensive. BTW, outside, diplexed to my dish (which has a clear view of the tower), this thing gets mid-90's on most digitals.