Originally Posted by dg9618n
... I was then told that all but Ping have the 2 degree limit. ..
Not true. On irons, TaylorMade can go plus-or-minus 4 degrees on lie angle.
Callaway and Adams can go plus-or-minus 3 degrees. (And, Adams hybrids have long hosels, and Adams can bend the lie angles plus-or-minus 2 degrees).
To find out the limits on bending lie angle, check the manufacturer's web site for the model you're considering.
Lie angle can influence ball flight. If the lie angle is too upright for you, you will miss to the left; too flat, miss to the right. Assuming you have a fairly consistent swing, lie angle and proper shaft length work together to help deliver square contact.
Here's a geometric explanation of lie angle effect from TST 2013: