In CS5 Color Settings what is the difference between photoshop 5 Default CMYK and US Webcoated Swap v2? I tried changing back and forth between them and didn't notice a difference in preview. Assuming no CMYK profile has been provided by a client, that you live in the US and your work is going to a high quality printer should one choose US Webcoated Swap v2 as a general CMYK profile?
I am also wondering what percentage dot gain dot gain to enter in grain and spot in color settings assuming your work is going to a high quality printer? What percentage dot gain is most common in high quality printing?