Re: Munich are implementing Kolab
I actually have been using a Kolab back-end for over 2, no 3 years now and it's solid. As far as all mobile devices are concerned, it's an MS Exchange backend with ActiveSync and behaves just like it on Android as well as iOS and OSX. I can't tell you how well it works on Windows and with Outlook as we stopped using that at roughly the same time.
I have used both Zimbra and OpenExchange before that, but that didn't quite work for us. They may have improved since, but I'm quite happy with what I have - it just works.
I'm cynical about user complaints, especially since the reports of Microsoft fandom of the chief Major (Dieter Reiter) (in German, sorry).
A similar situation exists in Belgium somewhere: the overall head of Justice IT is rumoured to be a devoted Microsoft fan, so everything that isn't Microsoft isn't even considered (mentioning Open Source is apparently a sure way to get sacked). The irony is that the bulk of their processing is currently on a very fast but aging Unix based platform, and I dread to think what will happen if they let MS loose on that. I suspect the same will happen as during the New Labour time in the UK when MS was allowed to flood the corridors of government: absolutely *nothing* will work, MS will help itself to quite a large amount of the tax payer's money and it will take many more years to fix the mess.
It's worth observing who will perform this evaluation. If it's one of the bigger consultancies you can forget it, it will be Microsoft again - I'm sure I don't have to go over all the reasons why (if you need a hint, think of what provides the best long term revenue for a consultancy: something that just works, or something that needs continuous propping up).