I am suffering from the same problem. Even with -65/18 readings I can barely get .5 Md/s. But my upload hits 1.5Mb/s.
I am assuming it's a tower capacity issue---I am in the Portland, Oregon area which was one of the first Clear areas.
I do have my antenna behind a window, but I don't think that would drag my numbers do too much. I've tried aiming at several towers and can barely get 1Mb/s at times...
every 15mins~, connectivity pauses for about 30 seconds. this started in past month, and is really irritating as i work over SSH.
any time theres moderate snow or rain, it drops out despite a -35dBm signal and 35+ dB S/N , so clearly theyre also using 2.6 GHz for longer intratower hauls and not running fiber/copper to each AP. disappointing
finally, their battery backup is terrible. trees take out powerlines fairly often here in wind gusts. and after an hour, their tower loses its battery backup. despite the weeks i could run tablets/puck off carbattery