Replacing hardwired fire alarms with 10 year sealed alarms
Bad idea.  Since the hard wiring was a building code requirement, a change could readily give your insurance company an excuse not to pay in case of a fire.  

In addition your detectors are interconnected, so they all go off together.  Wireless connected models are not available with ten year batteries ( I wrote on this topic at http://www.squidoo.com/you-have-three-minutes-to-escape-linking-home-smoke-alarms )

Instead consider pairing new detectors with ultra long life 9V or AA lithium batteries: such batteries cost more but last longer. And it's worth highlighting: smoke detector electronics generally come with a ten year rated lifespan (dating to 2004, as you note, yours are due for replacement).

Perhaps part of the problem was detectors that eat batteries?  The hardwire alarm batteries only come into play when power is out: a two or three year lifetime for each battery is the minimum you should expect, even from a conventional alkaline.