I've read a review or 2 somewhere ( Cant remember ) but don't know for sure, but they are supposed to be Excellent drives as far as their access time reading CDR and CDR-W media. That's about all I know . I haven't heard any negative comments about Toshiba.
As far as slot load, their is really no advantage other than what you see. They are not more prone to dust as they have the felt that seals the drive. When the CD is inserted, it spreads the felt just enough for the CD enter the drive. Just like a CD Player for a car stereo.
I would think that the slot load may even last longer. I say this becuase the tray load systems tend to wear and get sloppy after extended use which may slightly alter the placement of the disk in the drive. As a result, this slight altercation could cause interference between the capability of the laser reading the CD. Of course, this is my own theory and others may disagree. I owned a 4x burner and after extended use, it started to act up a bit so I bought a 12x. Ive owned my 12x drive for 6 months now and have used the heck out of it and so far, there are no signs of wear and tear.