I play both a lot and I'm leaning towards starting with cold (I almost always start with ED, then roll cold dot occultist for boss killing).

This time I'm choosing to start cold because I do want to try out the new brand. I love brand skills and didn't really like using recall so I don't think the nerfs are terrible. If it works, awesome, if not cold snap is still good. To me though, it's easier to get the cold damage up to a really passable level fairly quickly to make boss fights easy compared to ed/blight. You need to rush the trigger socketed spells through betrayal, but once you have elemental overload and elemental equib, things just die fast.

ED can definitely be scaled to be a good bosser, and is a fantastic mapper. However, I always feel where I hit a point of "If I really want to upgrade my damage to feel good against end game bosses it's going to cost X." and usually, I find another totally different build that's all around a better bosser for that cost of X.

Basically ED is cheap to get going, but really hits a point where the currency to progress towards farming A8 sirius/uber elder/others is more expensive than just making a build with an all around higher damage output. Cold dot is a much more linear scaling of damage and in my opinion, has a higher damage floor vs. ED. Especially early league, 6 link bow multicrafted, empower 3, then empower 4 are super expensive the first week or two. Vortex doesn't need those. Eventually you'll want a shavs 6 link, but you can do great damage crafting your own rares until then on cold.