I recommend the Odyssey PC680, but not the SpeedCell, for the street.
The principal advantage of using a larger battery is to be able to restart repeatedly and to have a cold weather reserve. If you regularly don't ride long enough to recharge fully between restarts, stay with a larger capacity battery. Deep discharges will reduce a battery's life. A lower amp-hour battery will need to be trickle-charged more often.
It also depends on the year of your bike. In 2001, all the superbikes were fited with a revised starter motor gear ratio that drew less current and made it possible to start the bike using the new smaller OEM battery. The starter gearing on the early bikes are not well suited for use with the smaller batteries.
For the street, especially if you live where there are cooler seasons or ride in remote areas, it may be unwise to trade-off weight reduction for the reliable starting you get with the reserve capacity of physically larger and heavier batteries.