I notice that all lat machine long bars slant downward toward the ends while it seems most pullup/chinning bars are straight-although some are slanted–if trying to build width in upper lats which bar would be better and what different effects come fom pullups on a slanted bar as opposed to a straight bar?-thanks.
The slants at the end of lat bars were made for two purposes. 1. to reduce wrist strain by keeping the wrist alignment more neutral 2. allow you to have a greater range of motion by allowing your hands/arms to travel further back and down before the bar touches your chest. For mass and strength purposes, real pullups and chinups will be better than the lat pulldown. I would not worry about the extra ROM of the slant bar until you can chin, with weight from a dead hang until your chest touches the bar, slow and controlled on the positive and negative. That will give you much better development than an extra few inches of ROM by sacrificing form and load. Depending on the length of your arms, to grip the bar on the slant will often times lead to a handspacing that is too wide and can lead to shoulder trouble and less than optimal lat ROM and activation.