i have a question how does the video work mixing them if u just have the sl1 or the sl3 with the crossfader of a regular mixer will the videos be able to crossfade an mix?

you either use your right and left arrow keys to crossfade the video or hook up some sort of midi controller. For some this is too many devices. I've been using an m-audio x-session pro, but it's awkward to remember that you've got 2 crossfaders to mess with.

Personally, I'm saving my money for a 57 or if the gods are on my side, one of them new fangled 68 mixers when they come out.

What kind of mixer are you using carlton? If you're using a midi mixer you can simply use an M-Audio Uno cable and map the functions onto the crossfaders of the mixer (i.e. DJM 800)

oh ok i just have a regular 2 channel vestax PMC-07 Pro, guess its bout time i to get the 57, if i buy the software would i be able to use it on my dj friend pc until i get my new laptop or it can only get installed on 1 system cuz ill just use his system until i get my new mac

When you purchase the Video-SL plugin you can install it on up to 2 computers. You can only use it on 1 computer at a time though, so once you get your own Mac be sure to deauthorize it on the laptop you are using before authorizing it on your laptop.