Transfer rate is reduced when not using the proper capacitors. As long as one uses the proper caps the datasheet guarantees some specified limit. The real point is whether or not the non-specified capacitors guarantee a specific transfer rate and if the required transfer rate stays within those confines. One can blatantly disregard the datasheet and the required results can be had, but are untested. If one does not listen to the datasheet, they had better know what they are doing and should have considerable experience. Why not use the 233, or 233A so that maybe people do not complain about capacitors :).