That would depend on the interface and the SD and CF speeds. There are 1000X Speed CF Cards (used in high speed motion photography) that can out perform any SD card out there. But it still remains - the speed of the IDE Interface is the maximum allowable speed possible.
On older Macs, the IDE can be 33MB/s, 66MB/s, and you wont see 100MB/s until you reach G4 systems. Thus the fastest CFs you can put on these machines are 200x, 400x and 500x. Another problem is that the CF>IDE interface may have some issues of missing lines. For the fix, see:
http://www.fccps.cz/download/adv/frr/cf.html
But this is only for DMA/UDMA support on IDE. This is not supported on an IDE that is 33MBs in speed; which on Macs is all the 040 Powerbook. It is also on the PowerPC PowerBooks up to the 1400. So you are stuck at 33MB/s when CF > IDE on these machines, that means that putting a 200X CF is the fastest you can put in as anything faster is just a waste as the higher speed will not be seen. (This applies to PCs as well as Macs.)
Using an SD card, even if it is faster an CF, you will hit this brick wall head on - it will never be faster than the interface speed allows. So you will be stuck in the same place I am. At least I can get from a CF Boot times of under 15 seconds on a G3 with OSX, and under 30 with my 190 and Wallstreet G3 but that is because there is a long pause of over 15 seconds between the Happy Mac icon and the loading of the first icon. Once it passes that pause, the extensions load up rapidly!
The SD > IDE should work on the Macs with IDE. Though there are a few rare cases when adapters do not work, in those I tried they do (Note: I have not used an SD > IDE Adapter yet). 90% of the stuff I used work. There is an occasional bad unit in the group, which is why I buy more than one.
You should see if that SD > IDE adapter you works on a PC before moving it to a Mac. And if your Mac has PCMCIA, you should have a SD>PCMCIA to try out as well. Macs can boot from PCMCIA. PCs cant without some difficulty.
Lastly, it's an IDE Interface adapter. There should be no driver and be plug & play. When did you had to install a driver for hard drive?