I disagree. :) I have experience in low level programming and several MLs (and lots of misc other languages), so I don't think my opinions are shaped solely by familiarity.
There is a lot to like about Rust, but here are some things that I think make rust hard (and I think the difficulty of these features outweigh any productivity granted by the safety features).
First, the affine type system--I don't understand the use case for pushing ownership deeper into the stack by default, and it seems crazy that I have to know how all instances of a given type will be passed at definition time. It doesn't seem to facilitate safety, or at least it seems like the most flat-footed approach to preventing double-frees (never let two functions access the same memory, even those that can be trivially proven to run sequentially). I literally never want to move--I always want to shallow copy (or reference). Further, you can't call most pass-by-value functions from inside a pass by reference function because the former usually wants to destroy the value. Copy works around this in the simplest cases, but for the most part you end up with two categories of classes that can't be mixed. This is especially bad for open traits, where the trait definition has to decide how all implementations will pass and receive their arguments.
Beyond that, when defining a struct type that holds a reference, you have to know at definition time the lifetime of that reference, even it may vary from instance to instance (sometimes I want the struct to own the reference, but sometimes I don't). Maybe there's a way to express this in Rust, but it seems like the default is to assume that lifetimes are part of the type. This creates another dichotomy in types: those that own their data and references to data (String vs STR, vec vs slice, etc).
I like Rust. I love that it's an ML with a sane syntax, or a C-family language with decent functional features and sum types. I just can't justify these impediments. :(