It's telling that Google has lots of experience with containers, because GCE is a smoother environment to deploy Kubernetes in. Perhaps the most visible is the one-IP-per-pod/one-IP-per-service design requirements of Kubernetes, which fits directly into GCE's super-flexible IP address space (an amazing, modern L3 SDN), whereas on AWS you have to work around AWS's creaky, old-hat VPC system and its positively stone-age security group system. As a result, a lot of people are resorting to overlay solutions like Flannel, Weave and Calico (overlays on top of overlays!). GCE's networking, in short, is amazing, and AWS's isn't.
GKe's automatic cluster setup is also impressive. GKE will create a master for you and you just tell it how many nodes you want. Disappointingly, the Kubernetes dashboard is not integrated into the GCE admin, but it's likely that they're working on a new one for that. Because of the lack of a UI, though, GKE feels a bit unfinished right now.
That said, it's obvious from even a casual glance that GCP as a whole is a lot less mature than AWS. The SDK situation is a mess compared to AWS. Google's complicated style of authentication is particularly onerous on developers. Google's services feel less nailed down than AWS; for example, CloudSQL exists as two (incompatible, afaik) versions, and there are multiple APIs that are marked as beta-quality (Google is slowly adopting gRPC throughout their system as an alternative to REST APIs). Some of their services offer odd design decisions; for example, Pub/Sub is clearly a clone of SQS, down to its more annoying features (no proper fanout support, and plenty of latency), but it also innovates on it by supporting "realtime" delivery... which for some reason only supports push events. Go figure. Overall, Google Cloud Platform feels a bit half-hearted, unpolished and ramshackle in many places, even though clearly there's a lot that is technically solid. This impression is partly due to the messiness of the documentation. As with Kubernetes itself, it seems Google likes to developer faster than they can document.
I do think that GCP will, in time, be much better than AWS. They are clearly innovating in many ways that Amazon isn't, especially in containerization.
How so? For us, the JS SDK for GCP has been way better than AWS's, and authentication "just works" if you're running from within GCP. With AWS we hit a pesky, wide-spread bug with random authentication failures [0] that hasn't been addressed in almost a year.
The primary difference on AWS is that you are doing all of this yourself instead. This isn't bad for everyone, but I've got the option of having Google do it in addition to doing it myself on GCP.
As a bonus, Kubernetes abstracts a lot of inter-provider differences away. I can move between providers more easily, or even run across multiple providers (cluster federation).
ECS is severely limited and slow to evolve, by comparison. They got to market first, but their overall container strategy is now inferior to GCP's.
They're still ahead in many other ways, though. I just feel like containers are GCP's sweet spot.
