Eset's malware responisveness is excellent, they are the best when it comes to how fast they react to new threats. Their malware teams generally push out definitions for threats that are submitted within one day. They are very configurable, but you need to do some research to know how to use it properly. However, they seem to be quite slow when it comes implementing new features. Their interface does not change for ages too, so that can be a minus for some.
On the other hand Avast pushes out new features at a rapid pace. They also have a far more modern interface than eset. Not as configurable too(which can be a good or bad thing) However, their new features, while decent are not very effective in some cases.
Both are decent. You choose the one which you personally like, not what others like. If you want you can run a trial of both and see which one you like. Cheers.