Since the top flap of the Tamrac 4390 covers the front pocket, you'll first have to unclip (and/or undo the velcro) before getting access to your accessories. Not really a big deal, but if your camera is stowed at the time, you'll have to take care it doesn't slip out when your fetching a spare battery or SD card.
The Case Logic 302 has independent zippers, so it doesn't have this issue.