Important things to note:

• The ChangeLog for the binaries is here: https://github.com/dave-andersen/fastrie/blob/master/ChangeLog
• The difference between the builds is fairly minor - it's built against a multi-architecture version of gmp. sse4 should run on almost any reasonably modern CPU. Only sse4 for Windows. grab the .exe for windows and the non-exe for Linux.
• 2% dev fee by default, adjustable from the command line. If you dev more than 1.5%, then 0.5% is split between jh and clintar, and the rest goes to dga.
• MEMORY: By default, it sieves to 500m. If this uses too much memory, run with -s 200000000 (that's 200m). If you have more memory, try -s 900000000 (900m) and it may get you faster performance. As of b14, with a fast CPU, you might go up to about 1.5 billion (-s 1500000000), particularly if the difficulty is high.
• While the reported numbers for 2ch and 3ch should be higher than existing miners, they don't reflect the real performance - particular 2ch. 3ch is a little more indicative, but compare the miners head to head for a few hours on 4chains/shares. This miner sieves all six positions and matches the new share definition (any four prime) that ypool supports.
• It takes a minute or so to really get up to speed.
• Known bug: At startup, the miner occasionally reports errors on submitting shares with an invalid merkle root. If it happens, do not panic - it will stop after 4 minutes at most. If it continues longer than 4 minutes, please post a bug report, but otherwise, don't worry about it.
• If you change -s, you will change the ratio of 2ch/s to 4ch/s. Higher -s will have fewer 2ch/s relative to its 4ch/s rate. Always benchmark and check your share rate - that's what you really care about.
• Use at your own risk. It may be buggy. It probably is. Always monitor your miners. There's a known bug that it doesn't always reconnect if the pool disconnects - you are strongly encouraged to use a wrapper script that restarts the miner.