I decided to do a follow up to my previous post because a lot of arguments I wrote down apparently appeeared in the other post mentioned by @Stefan. I will do a product review of the Shift7+ in this thread (because I think it fits there more) if you are interested in that.
First of all I want to say that for a lot of crowdfunded products the fulfillment of their deadline is a problem. This is not unique to Shiftphone or Fairphone but happens to most Kickstarter projects as well. That said, a “high-end phone delivered in Q3 2017” can easily become a “mid-spec phone delivered in Q1 2018”. When Shiftphones started their crowdfunding campaign in 2014, the Shift7+ was considered a high-end phablet but the actual delivery date changed from Q2 2015 to Q1 2016 (same with the FP2 which was promised for Q3/Q4 2015 and delivered Q1 2016). This is something you have to keep in mind when watching for crowdfunded campaigns.
As a security engineer, I value the monthly updates way higher than upgrades on Android 6/7 because this is something unique for Android smartphones. Even Samsung provided only 3-4 updates over 3 years for my Galaxy S3 although they have the biggest market share. So if you care about updates, don’t focus too much on the upgradibility to Android 7, since you will be able to run most apps on 6 anyway. Monthly (security) updates are far more valueable than an upgrade every 1 1/2 years.