https://forums.butterflylabs.com/announcements/4414-monarch-information-2.htmlJosh says:
Free performance upgrades
All customers who ordered 600GH Monarchs prior to the price decrease on November 28, 2013 will be upgraded to the Imperial Monarch product, which is a new, high performance version of the card. The Imperial Monarch will operate at 1 TH/s (+ / - 20%).
This is how I see this compared to the other offers:
scenario 1: bitcoin drops to 100$ - you take the refund anytime until ship date, you lose ~2000$. This in turn becomes the best offer available on the forum because you are able to convert this order back into money via refund. Every other order anywhere on mining equipment you would have lost much more on your investment.
scenario 2: bitcoin stays the same or goes up in price, and difficulty increases slowly - other miners would be more profitable, this would not be a good offer then but you would still not come out too far behind.
scenario 3: bitcoin stays the same or goes up in price, and difficulty increases very quickly - Its probably a wash then and depends on the exact scenario, because then people would only be mining with the most efficient products. At ~.45W/GH at the chip level this would be one of the last things to be turned off. Much of the gear available now would be turned off much sooner than the monarchs.
Thanks