Is it simple to make a claim with Ergo directly? How is their service like? Is it efficient?

Depending on the class of insurance you are purchasing from them??

I've worked with Ergo before, they are still very much agency based and they're not particularly large in size as a general insurer in Singapore to focus their resources on individual claims. IMO.

I would say, they are quite customer focused, but there's no guarantee service standards or a reputation build up yet, like AIG.