http://www.hdtvprimer.com/ANTENNAS/comparing.html indicates the older version of the CM4228 had some gain in the high-VHF band. If the data is accurate, there will be a 4 dB slope in the gain over the bandwidth of channel 9... that may pose a problem for some tuners and you're already facing the fading that comes with a 2-edge path. The author at HDTVPrimer also refers to knowledge of a new design coming to market which is consistent with the review you cite. The review you cite is almost impossible to verify as good bad or indifferent.
If KCTS-PBS is a must have, I would recommend using an antenna that would offer some certainty of reliable reception over the 2-edge path you're facing. So, back to the Winegard HD769X series.
Or, a combination of 8-bay panel plus a high-VHF auxiliary antenna if you are unable to get KCTS reliably using the UHF panel antenna. My previous high-VHF recommendation aimed at KCPQ-FOX. If you choose the panel antenna option and it fails to provide KCTS-PBS, I would suggest using either a Winegard YA-1713 or Antennacraft Y10713 aimed at Capitol Hill.
I'm wondering what your 10' or 15' prediction looks like... I suspect it will be slightly less optimistic than the 25'. Let's use a TVFR with the elevation or the installed antenna.
Finally, because you are renting, would a
non-penetrating roof mount be viable in your situation?