http://www.cryptocoinsnews.com/news/review-antminer-s3-450-ghs-bitcoin-asic-miner-bitmain/2014/07/25The Bitmain Antminer S3 Bitcoin ASIC Miner is their next step in the evolution of their ASIC chips as well as going back to the basics with the blade design that started it all. There are some changes that have been made along the way though. First is the cowled dual fan enclosure that the S3 has is a new twist on the first-blade design. They also made overclocking easier as well. The Antminer S3 was initially announced to run at a 478 gh/s and then revised down to 440 gh/s.
It is only a matter of time when will every old miner become outdated and non-effective, and rare are the ones that will ROI in the end.
It seams that bitcoin brought most interest on itself by earning opertunity that mining generates, and has created an oversaturated field.
Bitcoin mining is becoming(actualy more like it allready is) industrial operation, leaving the small guy behind, that being said; i would never again invest in mining equipement.
Sadly, i'm now in this same boat. Last year i was starting to mine BTC and was really excited! Being a part of a pool and generating .1 btc a day was something i really enjoyed seeing! Now, with the same equipment i'm generating roughly 10% of that! It's crazy to think how high the difficulty has gotten in such a short amount of time.
But, like you, i'll probably never invest in mining gear again. The return on investment is too much of a gamble.