Jobu LF-C504M2 drops centerline of mass (is that correct term?) ~22.5mm on 500 II vs. Canon foot w/DLP-115. Plenty of clearance for reversed lens hood. As a carrying handle its fine, but not quite as long or comfortable as Canon. Plenty of knuckle clearance for my skinny XL hands, heavy gloves may be out. Canon 300 foot just under 22mm shorter than 500, so 300 will have little position change, in use. Foot has 1/4 and 3/8 threaded holes near center (no inserts).