The main benefit I find over Google Maps is that Earth can display train/subway lines on the map. Immensely useful when I am trying to contact somebody for work and they’re somewhere in NoVA. Type in the address, and a quick glance will tell me if it’s within a reasonable walking distance of a Metro station.
It’s also a lot more flexible in displaying driving directions. Being able to quickly zoom in and out of specific parts of a path that seem unusual (and if DC beltway onramps and offramps are anything, they’re unusual), skipping over long sections of straight road, easily map gas stations or restaurants or parking garages over a travel route, all easy in Earth.
I’ve also been able to look through the layout of golf courses before putting down good money to play there, as well as just finding new courses that don’t advertise much.
Can i just say that, while i love playing around with Google Earth on my computer, i find that if you need map/satellite stuff in your browser, then Microsoft’s Live Search Maps generally offers better functionality than Google maps.
I had always just used Google maps, and i generally avoid MS stuff on the web because a lot of it is not very good, but i recently read a PC World review that gave the MS online product a very good review, so i gave it a shot, and i really like it.
Of course, each site has its own idiosyncrasies, and each site has its strengths and weaknesses, but i think that Google maps have become such a default application that people sometimes forget to even ask if anyone else is providing a better product. I know i did, until i read the PC World review.