1/2 IM bricks

I've got my first 1/2 IM race on Sept 11 but I'm thinking about my training plan and how to prep for the long course.  Is there any reason to do race-distance bricks as part of training?  For example, should I be looking to fit in at least one 56/13 bike/run brick before I begin my taper just to be sure I know what the distances feel like back-to-back?  I've got Oly distance races planned for June and July but nothing in early August.  I'm not currently using a specific training plan as I've been focused on base training the last few months.  I'm starting to add some tempo work (Z3) and a few scattered road races here and there.  I figured I'd pick up on a 1/2 IM plan around June to help me build up the distance and get the proper brick type training but I'm currently running and swimming reasonable distances (10-12mile LSD runs and 2500-3000m swims) with no problem at all.  My bike rides have been shorter but that's mostly because of the weather and my recent work schedule.