Personally, so far anyhow, they do nothing to impress me as a long term high current motorcycle starting battery unless weight savings is a major factor in battery choice. Might be a good choice for racing or a light weight off-road bike.
The Shorai is a Lithium Iron construction. Strong points are light weight & long shelf life without losing charge.
Disadvantages are a need to have controlled re-charging, decreased capacity with age, so far unproven in long term motor vehicle use. Some can have a decreased extreme cold weather power output also.
The auto companies have been looking at them for weight reduction but so far there have been enough concerns & durability issues that they aren't currently being used for high current discharge conventional starting batteries.
They do seem to be working good in non automotive application for back up power supplies & such & for non high discharge starting applications.
Quite a few people now installing them as replacements in motorcycles & power sports vehicles but not enough long term power sports usage yet to prove them out or to show me they are worth all that extra money.
Sent from my rotory dial wall phone!