Yeah, you won't get "as bored as quick" with the map, but the odds that you'll get tired of spending half an hour to get to a destination just to mess around for 10 minutes is pretty high. No one ever thinks of that.
True, but there are ways around that. Taxi's are a good example.
Would be fun if a large map had the same detail into it that GTAIV had. I always found interesting things to do online with my friends involving building stunts such as parkour etc. The buildings on GTAIV are great for that.