Hi Allan I've had both, and each has its advantages and disadvantages.
The disadvantages are that it is simply not as strong as a poured foundation. Not that you'd ever do this, but you could easily break through a cinderblock basement wall with a 12 lb sledge....but you won't be able to do that on an 8" poured wall. This makes cinderblock walls more susceptible to strong hydrostatic pressure (from say a heavy rain and concurrent snow melt with water saturated ground). I have a good friend whose parent's house in Up State NY had an entire cinderblock wall 'blow out' under this type of very wet condition.
The advantage of cinderblock is that hydrostatic pressure can be readily redirected by drilling or tapping small weep holes in the bottom of the cinderblock cloumns, allowing the water to run into a perimeter drain and to a sump. With a poured wall, any seepage will have to run down the wall and into either a surface drain or down a vapor membrane to under slab drainage.
This has been my experience with these two walls. Perhaps others can chime in who have had more extensive experience.