Don't want to derail, but since we're talking different nav setups and this particular setup, I've recently been using my dad's old Alpine IVA-W205, a Garmin nuvi 1490, and an Apine INE-S920HD up a bunch lately. The IVA-W205 is just plain outdated: it's a few years old now so a lot of missing roads in new subdivisions less than 2 years old, POIs that don't exist anymore, and dated as hell of an interface. The Garmin nuvi 1490 is running the 2012.1 maps at surprisingly it isn't great either. And it had more difficulty finding satellites compared to the much older Alpine INA-W205.
The INE-S920HD is fantastic, but then it again it's super new/updated, so that probably helps. I live in a brand new subdivision in which google satellite still shows construction (shingled, but no sod yet), and streetview doesn't even show the structure yet, and the INE-S920HD is the only one that has my street on it. Really quick to fix position, even in bad weather, which often gave the Garmin issues.
I'll try updating the Nuvi 1490 with the 2013.1 map, and see how that goes.