Both London and Berlin are excellent locations to hold the conference and there are many people on both sides arguing for London and Berlin.

In London, December's average LOW temperature is HIGHER then Berlin's Daily Mean. London's average HIGH is almost 2x that of Berlin's (wikipedia Climate charts for the cities)

Obviously we can pick only one city. Obviously we cannot throw a conference in both locations as to throw a quality conference takes a huge amount of effort. After long thorough thought we realized London was the by far best place we could throw the best conference.

We can guarantee a much wider audience which will make it a much more successful event (last year's conference, while being a great conference was a financial loss to us and while we love our projects we cannot continue at a loss - we still have free projects like libbitcoin which are a huge cost in terms of opportunity cost). In London, we can certainly bring a much better quality of speakers also which of course will increase attendance and of course the quality. We can organize things in a lot more of an economic way because we are based out of London.

Even for those traveling cheaply we are looking to provide low cost options in London. While we don't have anything concrete yet, we are looking at the ability for a venue (most likely not the conference venue) to allow for people to stay overnight at incredibly affordable rates.

We are hoping for a conference date earlier than December however venue costs will be our largest overhead cost (aside from our team's man hours for the next few months) and we must take venue costs into consideration. However, all things being equal (or close to equal) we will have the conference as earliest as possible.

We understand that if we have the conference in London some people who prefer Berlin will not be able to join us. We also realize if the conference is in Berlin there are many people who live in the UK or would travel to the UK that would not attend in Berlin. While making a choice like this is hard, the aforementioned variables make a London conference better quality and value for the majority of people. We hope to have information in the next 2 months as to if we can arrange for more affordable accommodations in London (something we will likely be able to arrange.)