I agree man, it's a good indicator to what you might need to work on. Also with your bench Hamburglar, whats your lat/upper back strength like?
Another indicator for shoulder/lat weakness can be which direction the bar falls out of the groove when you fail on bench. Toward the face can be either lat weakness or inability to get tight (the "break the bar cue" can help) or toward the feet can mean you are too tight and need some shoulders to stabilise better.
Mines 70:115 using the same grip, so ~60% and yeah I do see shoulders as a weak point that I'm working on but don't do strict press 1RM very often.