You may read the datasheet and then find you card is not even close. This happened to me recently when my SanDisk card turned out to be counterfeit Counterfeit SD Cards. - Storage - Arduino Forum. Your article about fakes is true, I now keeps a collection of fakes where I have been ripped off.
This was from an Amazon seller. If you buy an older smaller card now, the chances are very high the card will be fake. Forget it on ebay it's a coin toss. I don't think many sellers know they are pushing fake cards.
Major manufactures no longer produce standard, 2 GB or less, cards so the market for these is full of fakes.
Most cards are now used in phones and power consumption is becoming a bigger issue. I recently bought about a dozen microSDHC cards Benchmarks for new SanDisk and Samsung MicroSDs - Storage - Arduino Forum. I should test this batch for power use.
Once again, the datasheet won't tell you much for use on Arduino. I recently did tests with cards on SDIO using large multi-block writes on a high end micro. The performance is totally different than on SPI with the same card. I get read/write speeds of 20 MB/sec on SDIO so there can't be much extra flash programming.