Also, I don't think source was intended to be used with outdoor maps the size of Empires. I believe Keef made an outdoor map for NS1, though it didn't work well with NS1 game design (i.e. Marines went jet packs and flew around the map). This wouldn't be as much a problem with Empires.
So the NS2 editor, as it stands, is pretty cool but very limiting. You basically make everything with extrusion and a bit of edge/ vertex manipulation. The editor tries to be 'smart' in a way that hammer is most definitely not in the sense that it guessed what you want to do and takes out extra steps (to make a room, you just extrude a plane the other way). There isn't a currently a displacement tool, but one is planned eventually. I think the general approach is that most of the map should be made with modeling software and only the rough outline should be made of map geometry. The engine doesn't bother with vis calculations or any of that, and it isn't complied. Making huge rooms didn't seem to phase it at all. (the source engine is just fine though IMO, this is just for curiosity's sake)
I guess I fell in love with Irrlicht. It's just a graphics engine, but it's in my opinion so awesome. You can extend it fairly easily with different physics engines (PhysX, Bullet, Havoc, Tokamak, ...) and different networking layers (ENet, irrNet, Raknet, etc). But there's one problem - it's still a lot of work. You also need an entity management system and a lot of other things. Nothing I have time for.
The UT3-engine would be the best choice if you ask me, it has a good working vehicle-code (I have driven the vehicles often enough to say that) and I read that Unrealscript kinda gives you "access" to the engine itself, at least more than the access we have to the Source-engine.
Wait, wuh? I'm sorry, but the lack of/minimal lag-prediction in UT3 makes life stupid. Period. Sure as proven in Empires if you do stupid things you overload the netcode in Source (v1 where turrets updated every frame anyone?) but at least it has a have decent system for those people who don't have <100ms ping. Also, it feels like Source has a much deeper level of customization. The problem is the giant amassed amount of code and not uber great streamlining/networked documentation. Granted, this means you can screw yourself over more easily (as with anything where you have more power) but that's life, grow a pair, and do things the right way. That being said, someone still needs to fix Empire's melee prediction system.
I have lots of problems with source netcode when working off of a weaker connection, and empires becomes almost unplayable. Which is not true for UT3. Also, http://www.battlezone3.com/ is working, must have been server downtime.
Have you seen a Empires-scale mod for UT3? Have you played it of a weaker connection? You are comparing apples and oranges.
Kane, I've simply noted an event I find occured in one game over another. I was responding to a previous claim that weaker connections on source net code had not been experienced. That was all. battle zone promises to be of a caliber similar to empires . I'll let you know.