This issue has been beaten to death in the past, but as the above posters note, it is a very individual choice as to which is better. There is certainly no consensus that night float is hands-down superior to a traditional call system.
As an intern I had a nightfloat system (BIDMC), and I felt like I was always rushing to get work done on my call night so I could go home to sleep, because I knew I was going to have to work a full day the next day, whether I went home at 10pm or 2am. It also doesn't feel particularly comfortable to sign out patients who you just met and admitted, who were only partially worked up, to the nightfloat. Also, as the posters above note, eventually you will have to be the nightfloat, which can be a lonely and very busy job.
As a PGY-2 I took about 11 months of q3-4 call as a neurology junior, and while it was taxing, I felt more in-control and actually preferred it to the nightfloat system. I felt that I had more ownership over my patients.