I run kops in production, and while we've had issues, the authors are responsive and super helpful. The problems we've encountered have more frequently been with k8s itself than kops; mostly been fire and forget except when I've gotta debug which experimental feature I tried to enable broke kops' expectations (or just broke). Ping me in the channels @justinsb mentioned if you want advice.
We're at three live and two dead (decommissioned) clusters with a two man team, and while we regret some decisions, most of the time it just works.
Using the default networking stack. Basic aws networking on k8s relies on route tables, which are quite limited - Only supports up to 100 routes. We had to use bigger nodes than I'd planned to stay under that limit.
I don't know if AWS has the disclaimer up anymore, but the default limit is 50 with limit increases available to 100 with "no guarantee that performance will remain unaffected"... or something like that.
What network type are you using, out of curiosity?
What is the concern with using bigger nodes then planned?
I agree the basic networking has a lot of limitations. Compared with added more layers with networking, I'd rather have a simpler setup with fewer nodes, even if they are larger.
We're at three live and two dead (decommissioned) clusters with a two man team, and while we regret some decisions, most of the time it just works.