QUOTE(Magik5 @ Aug 5 2009, 03:09 PM)

its the same editor they use for cs, hl2 and l4d, it obviously works for some people because theres so many decent playable mods out for all these games...<snip>
Yeah, but sifferent style of game:
CS, TF2: Both geared for small boxed multiplayer levels
Portal: small box rooms and corridors
HL2: differernt game architecture and more usable resources due to no multiplayer and mid level loading, unless you play HL2 DM...
HL2 DM: small boxed levels :'(
The level design focus is different for L4D - they've made some truly good levels with the tools they were using (hammer) but the nature of boxed levels means limited amounts of hills and troughs. Hills and troughs apart from making a better, more realistic landscape would also provide cover.
For me it would just make more sense to generate a landscape and add buildings and objects to it, rather than the resource consuming building everything as in game objects. Keeping the landscape separate would also allow people to create varied custom maps using the same base landscape, allowing for a faster turnaround of custom maps.
Don't get me wrong they did a hell of a lot with the tools, but personally for this type of game it didn't entirely suit the game engine and map tools