It would be great if we could get some feedback in the future from folks who have used these third-party memory cards for a while - are they reliable, are there any issues with vibration, stuff like that.
I know that the engineers at Garmin all breathed a sigh of relief when all the automotive GPSRs switched over to COTS (Commercial Off The Shelf) memory a few years ago - CF cards and the like. Garmin themselves are not interested in making lots of money off proprietary memory cards, they would much rather sell GPSRs. The high price for the Garmin cards is due to the very low production runs - and the ever-declining demand for these cards. The only reason that they continue to use the 'old' proprietary memory card format in the GPSRs that have marine navigation capability is to support the tens of thousands of marine users who have purchased Garmin chips that are pre-programmed with charts of their local waterways in the past.
The marine cartography has a much, much longer revision cycle than the automotive cartography - typically about once every 7 years for a marine chart. For this reason, a person who bought a marine GPSR in 2002 and is now upgrading to a new GPSR would be pretty cheesed off if they were forced to buy another (new) licence for the same version of map, because the new GPSR didn't support the old data chip. To aviod this problem in the future, all marine maps sold since about 2004 are sold on a big CD ROM from which the mariner uploads the map to the data chip, then purchases an unlock code - same as us moto riders. The only problem that remains is waiting a decent period of time before dropping support for the old chip format.
Michael