Web summit has become famous due to Uber raising so much funding during a chat in the pub but it has perhaps gotten too large.
The first night summit was very popular and there were a lot of great conversations but what became apparent was that there were a very large number of startup companies attending.
If you go to Dublin I strongly recommend going for a whisky tasting session at the temple bar. The bar staff are very knowledgeable and extremely friendly.
Oh, and there are some great places for live music too, whether you are looking for traditional folk or more rock covers.