The internal GPS may take sometime to pinpoint your location if you choose to not use AGPS (Assisted GPS) mode. AGPS utilises 2.5/3/3.5G/wifi to contact with a SUPL server of your choice in order to get your co-ordinates and using AGPS drastically decreases the amount of time spent on tracking your location and regardless of the weather you are in it will still pinpoint your location fairly quickly compared to just using internal GPS.

As for downloading of the maps to use with the Ovi maps. You do not necessarily need Ovi suite to download the maps, there are alternative ways but it all depends on how capable you are.