Multisite or Not

I will like some feedback and advice from the community. We are a web development company and we think it will be cool to consolidate our small budget websites into wordpress MU. Which is the reason why i joined wpmudev, it has been a long journey since last year trying out a number of things and fixing bugs etc. I am trying to make a move now on some changes, and here are my questions
1. will it make sense to just multisites for a development and then export over the site when completed as as single wordpress site
2. or do you think I should stick with wordpress MU
bear in mind I have different vertcials I am trying to target, so my initial intention was to setup wordpress MU for different verticals with their relevant plugin

my concern with wordpress mu is that if there is a major issue all my sites might go down while with separate wordpress sites. Of course there will now be the night mare of managing all the different wordpress sites. Except i can build a management tool that can integrate into all the different wordpress sites with single signon. Also with dashboard display info(version, users, updates required etc) about all the sites. That might be an interesting approach
I look forward to your thoughts