That code is the same, but or has a lower priority than ||, so they are not the same is the code before the or is an expression.
Also, using or instead or || for these types of things is more readable since it makes your intent of conditional code execution (as opposed to boolean evaluation) clear.
Meh, it's not more unreadable unless you have issues understanding || in the first place... and "or" is still a boolean operation.
Considering 99.9% of it's use in PHP is some variant of "connect() or die()", I stand by my statement. Besides, those "connect() or die()" expressions are widely considered bad-practice in the first place.
That code is identical to: