The best part about fast base, as far I can see it's their customer service team who are always there for you when needed most! They have been very helpful with my queries regarding our data privacy policy & GDPR compliance issues we were facing at one point during implementation phase (which has since resolved).
Their technical expertise helps us solve any issue related or not directly linked towards product usage/integration seamlessly without much hassle from end users' side too!! Not many but some small things like "How do i use this feature" - they don't make me feel comfortable enough even after multiple attempts :( Maybe its just because am newbie here :) But overall experience sofar great!