I've got two Optimates. I keep the ZZR 1200 on full time and it's worked very well. The ZZR is easy sinec they very thoughtfully fit the Optimate connection to the battery terminals as standard.
the world and his dog will tell you to get the optimate III. it detects the state of the battery, can repair dodgy ones, and will cut out rather than constantly trickle into a full battery.
Optimate, I have fitted a 'jack' plug in the seat unit and connected to the battery - makes connection a few seconds job - couldn't be arsed fiddling with leads etc.