I currently use an S3. I have three extra batteries (all of them look like those cheap ebay ones in the article) and one extended battery (4300mAh) which also looks like the same design - just much bigger. I use them in cycle with the OEM battery.
I also have three external battery chargers. This entire setup has cost me ~$25. The price for a second official samsung battery? $50. I never run out of power and even on long trips I have an Anker external for backup.
This phone is made to just drain batteries like no tomorrow. I experience the same or slightly worse battery life with the after market ones than with the OEM battery. I am able to always have a battery in the charger and swap as needed.
If I'd gone with the official hardware I would have spent $250+ on batteries alone.
I've never had a battery catch on fire, overheat or cause other problems. They work perfectly.
I can't support this article throwing out stories without any real proof. As mentioned, the Best Buy reference doesn't prove that all batteries are bad. Manufacturers usually buy from the same (or next door) factories and sell them for a massive markup - why am I expected to pay several times the cost for a battery that is likely near the same quality?
The only issue I've had is with laptop batteries - they die quickly and lose their capacity.
I'd take this article a lot more seriously if it had some actual stats or research to back it up.