Can someone tell me what Rendering Intent is? How much impact will the setting have on prints?
I take it we are making an assumption here that you are using 'Proof Setup' in relation to a specific paper profile and have 'simulate paper color' ticked and 'gamut warning' ticked. I assume also that you are using a calibrated monitor and expect to get a print that closely approximates what you see on your monitor.
If this is the case, then you can see the effect that the various rendering intents have on any particular image you are viewing, by toggling amongst the various intents in proof setup.
My impression is that Rel Col significantly dulls the image but tends not to show areas that are out-of-gamut. However, before printing with Rel Col the image always needs (in my experence) drastic increases in saturation and local contrast, which could result in patches of out-of-gamut colors then appearing on the monitor.
Absolute Col tends to leave the image looking pretty much the same as you see on the monitor but tends to show out-of-gamut colors in the shadows.
I often use Absolute Col when I'm already satisfied with the appearance of an image I don't want to significantly rework it in Rel Col.
If I want to make a big splash with fully saturated colors, I'll use Saturation Intent.
I always do my best to remove the grey splotches, indicative of out-of-gamut colors, before printing.