I appreciate the feedback, thank you!
I actually do know why the GPS was functioning that way. It has to do with the US-specific update I made with a modified GPS file from XDA, and that was what was mentioned from that dev as to be expected. While GPS may take a bit longer to lock on, the signal should stay strong consistently - all of which appears to have been exactly what happened, and there's unfortunately a trade-off (faster lock-on, less signal strength, vs longer lock-on, strong signal strength). By all means if someone can come up with (or even myself) a way to get the best of both worlds out of the box, I'm all for it!
In the mean time, there is something I can suggest that does allow you to get the best of both worlds essentially, though it isn't out of the box as I'd like it to be. There's an app called GPS Status that helps get a GPS fix quickly for any phone, using more satellites and updating AGPS data to allow other benefits as well. After firing that up, usually firing up Maps right afterwards on the OE should allow for a rapid lock-on.
In the interim, let me know if you'd prefer a build with the changes to GPS reverted - I can whip one up!
Hope that helps, and that the trip was nice!
-Artine