Honestly, I still think the biggest problem with DJs who already are using laptops is that it is now one more step to load music. EIther transferring to an external HD, USB, or internal drive found on the prime.
It's not a hard step, but it is one more thing to deal with. I think if one has never used a laptop, that wouldn't be an issue.
I like that fact that all my music never leaves my computer. Even with the Prime, a DJ is preparing and organizing their crates within software on a computer ahead of time, so...
Now, if a DJ is already using an external HD, and not sure why they would, then they are used to it, but that's a different discussion. You just have to have the database file which stores all your crates and other stuff.
The second biggest thing for me is the lack of a trackpad and proper keyboard that one would have on a laptop. The screen is a decent size, but it doesn't replace the preciseness of a true trackpad found on a laptop.
I honestly think it's going back in time. This would have been great in 2006 when laptops were getting big for DJing, but now that MOST DJs have gotten used to the GUI of Serato and like, it's going to be very hard to convince someone to switch.
I would also be really worried if the controller froze, malfunctioned, or simply died/stopped working. The whole show is over. At least with a laptop, you have a backup laptop.
But, I might be totally wrong, and Serato will be out of business and units like the prime will be the new norm in every club and every private event. Time will tell.