S II as a Sta Nav

I am purchasing an SII and was wondering how what people think of the SAT NAV functionality.  I am thinking of installing CoPilot as I will be travelling in France over the summer and want to use the phone as a Sat Nav without incuring high data usage costs.  Firstly, has anybody got any thoughts on using CoPilot?  and am I right that it will not download anything as the maps are local and it will only use the GPS functionality and not use any data usage?

Hope ou can help.

I haven't used Copilot but as far as I am aware it is similar to to Navmii's Navfree which I do use and recommend. Maps are stored locally on both Copilot and Navfree. Some lookups use a tiny amount of data in Navfree but it really is a tiny amount, you may even be able to set it to warn you or not connect.

Google navigation supposedly caches everything it needs at the beginning of a route and it's data useage seems to confirm this. Not sure I'd trust it when travelling abroad and if you spot a vineyard sign and take a detour it might end up costing. Better to invest in Copilot before you leave.

As for the GPS functionality, I can't fault it. Since the ICS update getting a GPS fix is near instant and very reliable. Prior to the software update it was pretty good but not 100% at getting a fix. I believe it does use the network to some extent to get these quick fixes but I do not know if any chargeable data is transferred.