Garmin 24K topo maps are not locked to a particular device.
According to GPStracklog.com (HERE)
the Garmin 24K topo maps in DVD and uSD formats are not locked and can be used on multiple devices:
"Garmin recently finished rolling out their new TOPO US 24K map sets. They are available as downloads and on micro-SD cards, with larger regions available on DVD. All three formats can be purchased directly from Garmin as well as various retailers. The new product offers several advantages including routable trails and detailed highway coverage, and the DVD and micro-SD formats are not locked to a single device, so you can still use them if you buy a new unit
FWIW, gpscity.com says the same thing...