Old Garmin?

Get a good 6xx or 7xx series instead.

Here is a quote from someone at Amazon about the Bluetooth feature of the Nuvi 360 that could be informative:

"What happens is that once your phone has made the connection with the 360, a phone icon appears on the Nuvi. You can now use the 360 to call ANY POI directly from the screen! This is truly amazing; you are now walking around with the yellow pages in the palm of your hand, sortable by your current location, or any other location you choose. I just find the Point of Interest, and touch the phone number of that POI, and the phone starts dialing it. The sound comes out through the speaker of the Nuvi, and conversations have been natural so far. It's working like an absolute charm"

I just purchased a previously owned Nuvi 360 and my conclusion is that this Bluetooth unit working together with a Bluetooth cellphone as described above is a nice feature to have as an option. I actually selected the Nuvi 360 over the Nuvi 350 based upon this feature.

Weren't these 3 models discontinued by Garmin back in about 2007?

I get your point, but I need this to connect to my Uniden Bearcat Home Patrol HP-1 scanner. It needs NMEA-0183 data, which I can get with an Argent Data cable connected to one of the following supported models:

Garmin nüvi 300 series
StreetPilot c340
StreetPilot 7000 series
StreetPilot 2820 series
StreetPilot 2720 series
zumo 400 series
zumo 500 series

I have pretty much narrowed that list down to one of the Garmin 300 series units for me.

Yes, they were discontinued several years ago.

While I have no specific knowledge on the 350 vs. 360 receiver differences, in general the introduction of higher sensitivity receivers over the years has greatly improved the GPS experience. (and I've been using consumer GPS receivers in cars for over 20 years).

To address your specific question, the main benefit is not generally in startup time--which won't directly be affected at all unless you happen to start up in a signal-strength challenged location. Instead the main benefit is keeping signal locked in places where the lower sensitivity would lose it. Some real-world examples of where it can make a substantial difference:

1. tree canopy (most obvious when hiking, but also helpful on some roads in a car). Given the small signal strength margin and the frequency of the signal, no GPS receiver will see through dense triple-canopy, but the higher sensitivity receiver will keep signal in denser cover.

2. location in car. With my modern GPS, if I place the receiver down in the footwell to get it a little farther out of sight when stopping to buy coffee, and forget to put it back in the dash, the guidance voice is likely to remind me of my error by calling out the next turn (this actually happened today). With the oldest receiver in my experience, just turning a corner on the open road, which would change which satellites had line-of-sight to the receiver through the windows, would often cause it to lose lock (a problem exacerbated by the fact it only tracked four satellites at a time--so on losing one had to go through the full acquisition sequence for the guessed-at next best choice--modern receivers generally keep the best twelve in sight, which is more important to in-car performance than a little sensitivity difference).

3. urban canyon trouble. Not just New York, but anywhere you have buildings blocking view, receiver sensitivity can help. It can also hurt--as such locations offer chances for multipath error. This happens when a signal bouncing off some surface is successfully received. The bounce means the path length differs form the direct line to the satellite, which throws off the pseudorange from what it should be, which eventually gives you a wrong location--sometimes by hundreds or even a few thousand feet.

As a bottom line, in comparing two GPS receivers one is considering, extra sensitivity is a good thing.

them all, but use my 765T, and wouldn't trade it for the world!