GPS - buy here or rent there?

Get the rental car with one. Won't have to worry about loosing it or carry it in your luggage. Enjoy your travels.

Advantages of buying here:
You can get used to it before you go by practicing using it even on known routes before you go.
You have it to keep when you return.
Usually cheaper in the long run if you intend to use it.

Advantages of Renting
No need to make sure it has Europe maps.
No need to carry it there and back.
You might get a geed deal so it costs next to nothing.
Not likely to be stolen from car.

We bought one here in the States for our trip this May. Here were our considerations:

1. As mentioned before, we would use it here as well, so we found it worth it.

2. We researched all the GPS systems (Garmin, TomTom, etc.). The problem is that if you buy one here, they come with US/Canada maps, not Europe. To buy Europe maps can be very expensive. Based on this we went with the TomTom One. I've seen it in ads for $149 and then Europe maps through their software was 50 euros, making the entire thing $225. Garmin wanted $200 for the Europe maps on top of the price of the price of the GPS. From what I understand, all you get with the more expensive models are more points of interest (POI), which may or may not be worth it to you. The One worked fine on a recent trip to Mesa, AZ. Not perfect on POI, but routes were spot on.

3. The downside is that we won't know if it really works in Europe until we actually get there. We can see the maps, but will it get a signal?

The cost of adding GPS to a rental car could pay for about half of one (depending on the length of your rental), so if you will never in your life use one again, rental is a better value.

On the other hand, when you rent the GPS in a foreign country, often there is not an english language option, so as long as you speak the language fluently, it's no problem.

If you want to buy, the Garmin nuvi models come highly recommended, buy the 270 or 370 with pre-loaded european maps. They also work here in the US.

Since I travel 30 weeks per year, I get lots of opportunities to try it out and find it quite useful - far more accurate than mapquest or google maps.

Just in case you need some more recommendations, look here: http://www.ricksteves.com/search/search.cfm?searchFor=gps (enter GPS in the search function upper right hand corner).

I think buying one here and taking it with you is the better choice. Having time to read the instructions and practice with it will undoubtably help you on your trip. When you come home, you can use it for finding addresses or vacation driving directions.

Would recommend you get one here. The Garmin Nuvi 270, 370 and 670 and the tomtom go 920 and 920t have Europe maps preloaded. Amazon.com seems to have good prices for these models.