IMO THE SINGLE TRIM MONO WORKS REALLY WELL , THE FLOCKED DUAL HAS NO SCRUBBING POWER ONCE YOU HIT STUBBORN BIRD MUCK YOU CANT SHIFT IT , CANT UNDERSTAND WHY YOU HAVING TROUBLE WITH MONO LEE , THE BRISTLES DONT HAVE TO SPLAY RIGHT OUT LIKE THE VIKAN BRUSHES FOR INSTANCE , I WORK FINE ALL DAY EVEN WITH 3 STORY TOWNHOUSES WERE ITS DIFFICULT TO GET FULL PRESSURE ON TOP FLOOR , ALSO AGREE WITH YOU DAZMOND ON MONO FOR LEADED WINDOWS IT DOES DRAG A BIT I GO ALONG TOP FIRST THEN DOWN EACH SIDE OF GLASS WITH ONLY THE EDGE OF THE BRUSH THE OTHER 70% IS LIFTED OFF THEN I SCRUB SIDE TO SIDE WORKING MY WAY DOWN THE GLASS THEN RINSE SAVES CHANGING BRUSHES AND ONLY SLIGHT DRAG HERE AND THEIR