I owned the original CD-Ripper and I found it extremely slow compared to any other dvd/cd readers, I hope they improved this aspect.
Other than that is extremely well built.
I don't know what extraction methodology iRiver employ on their CD-rippers for the AK line-up, but it might be that they are using more effective reading and error-checking routines than the vanilla 'jitter correction' that most computer ripping softwares employ. It takes a lot of extra time to re-read sectors on a CD, multiple times, in order to minimise ripping errors (much more info about this can be found on the website I previously mentioned, regarding
Exact Audio Copy).
Another possible influence on ripping speed is that modern computer CD ROM drives rip at very high speed but generate quite a lot of noise and vibration, and, perhaps, iRiver might have chosen a slower rotational speed in order to minimise noise and vibration for customers who may wish to listen to their hi-fi without any audible disturbance, whilst their AK ripper is doing its job.
Personally, I always choose quality rather than speed, when it comes to ripping my CDs, which is why I am willing to use EAC instead of 99% of other ripping softwares, which use embarrassingly simplistic and inadequate 'jitter-correction' routines.
Perhaps someone from AK can explain what aspects affected the design of the dedicated AK ripper device(s), but at least you can see, from the above, that there are sometimes very legitimate reasons for some rippers being slower than others, and it doesn't necessarily indicate a shortcoming -
in fact, it may indicate the device has been designed very well!