A boy meets a girl. A BEAUTIFUL girl. Also, spiritual and deep and interesting and fun. The first date was great but there was this feeling of "There is so much more here that I want to get to know better. A lot of intrigue." The boy hears back from the girl, "I'll go out with you again one time - in 7 and a half years...."
Daf Yomi has many, many mylos. Structure, breadth of knowledge, connection to other Jews studying the same daf, a feeling of accomplishment, kviyus, etc. etc. But there is an uncomfortable feeling I have about the whole project. Each page of gemara is soooo beautiful. Also, spiritual and deep and interesting and fun. I want to get to know the page better. To review the gemara 25 times. To master it. Then to look in tosfos and the rashba and the rambam and the pnei yehoshua. So intriguing she is. There is so much there. But the program requires that I move forward and only return 7 and a half years later. Of course one is ALLOWED to go deeper into the daily daf but how many people do?? It is no coincidence the the great bastions of Torah do not have daf yomi on their schedules and if they do it is only a minor part of the daily seder ha-limmud. This is because true Torah study requires depth that a superficial lets-get-it-over-with daf yomi can't satisfy.
So daf yomi is great but I don't think that it is ideal for one who tries to truly understand Toras Hashem is a deep, penetrating fashion.