blame valveThe only bad thing that i've experienced, is the limit on models (512) when loading a map with a lot of models and ECX.
your talking about doing it so the models are just one file aka they trans using submodels instead of the normal modelsTrue, I didn't really want to pin that on ECX as it could have easily been the mappers as well. But I really enjoy those interactive maps and I think their might be a way to "clean up" (so to speak) ECX such that there's less models to prechache but infact really it will be the same amount.
I don't know the topic 100%, but I think one can mesh sprites into a single file and know the correct beginning to ending sequence when animating. Technically meaning there can be one file for every character eventhough this would be taxing on the programmer.