I bought the Shorai LFX18L1-BS12 (270 CCA) for my 2006 Gold Wing from Wingstuff in May, 2011, for $159.29. I was very impressed with the battery and loved how I never had to worry about finding a dead bike due to battery failure.
However after accidently leaving a light on the bike for a couple days, I went out to find the battery totally discharged. I put the charger on the battery and brought it back up to 113.2 volts. However after removing the charger the battery would drop back to 110.1 volts within a very short time and remain there. The battery manual warned that a total discharge of the battery might damage it to the point of no recovery, which it had.
After reading the original warranty I noticed that an "over-discharge (i.e. resting voltage allowed to fall below 12.8V/6.4V for LFX 12V/6V types) might void the warranty, but if not so the warranty for a battery in it's 25th month would be prorated at 25% off MSRP. Since the MSRP was $189.95, I would need to pay $142.46 to get a warranty replacement.
However, just to see how they would handle it, I sent a warranty request to Shorai, including the information of the total discharge. To my surprise they promptly responded that not only were they honoring the warranty, but that they were upgrading me 2 levels to the LFX27L3-BS12, a 405 CCA battery. The MSRP on the upgrade was $275 and the Wingstuff price was $234. However they were just charging me $86 for the warranty exchange. Plus, they shipped the replacement out to me the same day, without my having to first send in my defective battery.
So my review of the Shorai batteries are that they are great products that should give you years of use but that the Shorai customer service is even fantastic by itself.