After being with Dyn for 8+ years, this last week I moved from them to Amazon. The Dyn interface is chaotic - so bad I contemplated just reverting to hosting DNS myself in PowerDNS/Poweradmin (https://www.poweradmin.org/trac/).

I never had downtime issues with Dyn, and the performance was satisfactory. But I tried talking a coworker through updating our TXT/SPF record and told him he'd have to "stumble around until he found the right interface" - at that point I realized we deserved better.