Yes, no need to paste whole text here (and to change color to unreadable one :-). There is nothing about that parity control bit and lower reliability nonsense. While the accuracy of details in this wikipedia article is not ideal it has all the important bits right and does not contradict anything I said. As you may see the compatibility isssues start already at 1GB boundary due to some manufacturers being surprised by block size over 512 bytes. 4GB cards are not worse than 2GB ones (except the FAT32 issue). Block size for 4GB cards is 2048 bytes.

Good overview is here http://www.hjreggel.net/cardspeed/special-sd.html