I actually returned from a week in Berlin just a few days ago, and I was specifically there to investigate whether it would be a good place to base my startup.

Just to be clear, I very much WANTED the city to live up to it's hype but it has one major problem that, for me, was a deal-breaker: attitude.

It is true that there are lots of good, reasonably priced restaurants, interesting bars, good public transport, cycle-friendly roads and reasonable rents (although not as cheap as some are suggesting).

It is also true, however, that many Berliners have a HUGE attitude problem and a completely illogical resentment of foreigners. I would say that the majority of my interactions with Berliners were positive but I also regularly experienced a snide, superior, strangely bullying attitude in service situations.

Now, you don't go to any big city looking for happy faces and warm hugs and you can shrug such incidents off, but it does wear you down over time. To give you an idea of the extent of what I'm talking about, I find much bigger cities such as New York, London and even Frankfurt, Munich or Hamburg to be far more friendly - yes, even New York is less rude!

The passive-aggressive attitude towards foreigners is a red flag for anyone hoping to run a business because that is absolutely going to crop up again and again in the form of local government red tape and an extra scoop of bullshit from landlords, suppliers etc.

More worrying is the aggressive-aggressive attitude - several times in the course of just one week, I witnessed open hostility towards foreigners, including locals interrupting guided tours to self-righteously tell the tourists - people who had travelled across the world to learn about Berlin, spend lots of money, create jobs etc - that they were not welcome. I have travelled constantly for over two decades and I have never seen that happen elsewhere, not even to obnoxious bus-loads of German tourists.

Fascinated, I discussed this with locals and was amazed to find that, even among people who would identify themselves as left-leaning and anti-racist, there is a general sense that foreigners are bad for Berlin, that they are responsible for the commercialisation of the re-unified city. Bizarrely, they don't see the connection between this attitude, this tendency to scapegoat foreigners for all unwelcome changes, and the slow-building antipathy of their grandparents towards the Jews in the 1920s and 1930s.

I am not suggesting that startup founders are going to be marched off to death camps, but you should certainly visit the city and, before investing serious time and money, think seriously about the realities of living in a city where you are not welcome - no amount of buzz or hype can compensate for that feeling once you are actually based somewhere.

Cities that I rate highly would be Singapore, Dublin, London and Santiago. Amsterdam and Paris are beautiful but not business-friendly. Australia could be good, great lifestyle, but they have lousy Internet infrastructure and ignorant government. Several American cities - SF, NY and even smaller scenes such as LA and Austin - could be wonderful, especially in terms of funding, and the lifestyle is good, actual Americans are very friendly/positive, but the current immigration laws are insane and do not take into consideration the jobs and wealth you will create. I don't expect that to change until the US disentangles itself from its various wars and is finally forced to face up to its growing economic problems, but that won't happen for at least another decade.