When I come across a question like this where many have already answered, I make it a point to read all previous posts because someone has probably echoed my opinion. In this case,
Litch has beat me to what I was about to say about photos. Both drawings AND PHOTOS are only
representations of the real thing. Therefore, claiming photos are better than drawings, IMHO, simply displays a lack of ability to use your imagination.
Having said that, I realize I'm in the minority when I say while I like photos, I
prefer drawings. My reason is simple enough. While I find many "real" women (i.e. photos) quite attractive for many reasons, I have an ideal that essentially REQUIRES a drawing to achieve it. IOW, my fantasy women don't exist in the real world (In my Bio, my list of Fav Big Bust Stars come closest).
Not to pick on
boobifanX, but his post shows the irony of some people who claim to prefer photos. He answers the original question ("IS it more attractive to you personally or less?"), quote, "For me: quite less. To be exact: nearly not attractive at all. etc.."
Now read his signature.. quote, "Big boobs should be nude, firm and round" How many breasts in real life can match his description of what breasts should be? In real life gravity rules, unfortunately in this case (not to mention clothing getting in the way for many photos).

Of course, a teardrop shaped breast in the hand is better than a photo OR drawing of gravity defying globes, anyday (in some cases).

Added: While my avatar alone could provide an example of my ideal, I'll bring back a thread and image that sums up my taste in the female form that was posted almost a year ago.
First a link to the thread (where you can find an index to the montage) and then the montage itself. I also uploaded a
photo montage of some ideal (to me) women in this thread..
Absolute ideal 