Since I rip extensively with EAC - I'll give you what I observed with the various drives I have used.
My personal opinion is that if all you want is the highest speed of ripping with EAC, you are better off with a CDRW not a CD/DVD combo or burner. And no matter what, if you want accuracy, you are not going to get a super fast rip.
The fastest ripper I have with EAC is the Sony 230E CDRW - speeds range from 8x to 16x and it handles problem CDs fairly well.
The Lite-on 1633S won't go above 3.5 unless I "trick" it ( I rip a partial track in burst mode, cancel, change to secure, and immediately rip the CD). But this drive also has the best error correction I have seen - got tracks the NEC (later) and Sony couldn't. However you pay the price in that really good error correction slows the drive down a lot.
The BenQ 1650 & BenQ 1670 which is rebadged I/O Magic and currently running Sony f/w rip at about the same speed about 6x with the edge in speed going to the 1670. I haven't had these long and can't say how well either will do yet with a problem CD as haven't had one yet. I do run into on both, one or two tracks that I have to rerip because of a Sync/Read error on good CDs in about 1 in 6 CDs. These I skip and the second time around they come up good. It is a lot faster in error correction than either the Sony or the Litey when it kicks in for the occasional spot (maybe because as far as EAC is concerned there is no C2 error correction on either of these drives)
The two NECs are elsewhere and are used for ripping infrequently - I don't have the model numbers as I never do a lot with these. The burner again is about 5-6x and the CDRW runs about 6x to 10x. Not as good at error correction as the Sony and nowhere near the Lite-on. This tho is based on casual observation as I can't go immediately from the Sony/Lite-On/BenQs to these two drives for comparison.
And there is an option in EAC under Drive options to not to allow speed reduction. This is unchecked for all my drives. Whether it makes a difference I don't know.
I also run into CDs all the time that no matter what the drive will normal rip at - these particular CDs will not go above 2 - 3x in ripping under EAC.
In the end you are going to have to do a lot of searching and decide just exactly what the specifications are that you want and look for a drive to fit that