I have the ACR AeroFix w/ internal GPS, which is exactly the same as the TerraFix and AeroFix, but I don't have the newer MicroFix.

Regarding your list:

1. I'm guessing you're asking what is in the SAR Users Click Here section of the registration database system. I don't have an answer to that.

2. There is a place in the form to put additional information.

3. When I first got the PLB I thought about getting a carrying case, but then I figured why? The PLB is plenty tough and completely waterproof already. There's no sense in adding weight and complexity. I might sew a little nylon case for it, just for fun.

4. No real change. I still enjoy buying gear. I still plan ahead, carry survival gear, and use my brain. The PLB doesn't go with me 24/7 - only when I'll be far enough from civilization or potentially out of cell phone range. The only real difference is now I know if something bad happens I'll have a great way to get help and be found. I tend to focus a bit more on making sure I can "last" long enough for rescue (think <48 hrs) and that I have the means to signal rescue crews when their looking for me.

5. The buttons on the PLB are plenty tough. Those on the Aero/Aqua/TerraFix are covered by a protective flap. Though the MicroFix's "start" button is covered another test button isn't. I don't thing that detracts from it durability at all.

The next big step up from the MicroFix or its offspring, besides getting smaller, will be when (if?) they start using the new generation SiRF StarIII chip that has an amazing ability to lock onto satellites. To my knowledge, so far the only handheld GPS's that have it are the newer Garmin GPSMAP 60 and 76 series.