Longer bows seem more stable for me, too. I feel my accuracy is much better with a longer bow, plus no stacking issues. Super smooth and quiet draws.
My Hill bows are 62", 66" and 68". I feel my 62" starting to stack as I reach a full draw (minimal - but at 66# at 28" I can start to feel it) but not so with the longer bows. They are 80# and 85#. I feel very accurate at 20 yards and pretty good at 30.
My shortest bow is Super Mag 48" 85# at 28". It is pretty accurate at a closer range - 15 yards.
My second shortest is a 58" Jack Kempf Kwyk Styk. But, it is a Jack Kempf bow so that mitigates everything. It is accurate at any distance.
In the end, I am a long, longbow kinda guy. I just love them.
Matt