the slide card has been proven to damage your DVD drive as it literally just hits a release switch and pulls open the tray manually. just think of pulling out the CD tray on your computer all the time.
the flip top lets you drop in a cd without even touching the cd tray. i highly reccomend it , i have one and it works great. and the install is really basic, you unscrew like 10 screws , remove a panel and put on the new top, screw it back together