Two points here really hit home with me about AWS (not in comparison to GCE though since I've never tried it).

1) Reserved Instances: I think the pricing model for this has become very outdated since the beginning of AWS, and it is definitely becoming cumbersome (and therefore scary) to use.

2) ELB + Traffic Spikes: I have tried (unsuccessfully) to pre-scale an ELB to prepare it for the traffic it was about to receive. I tried to pre-scale for this project 3 different times, in coordination with support and without them. I could not do it. Very frustrating.

I think these are all signs of extreme growth, and a strange organization of engineering units inside of AWS. However, as OP descried.. we are much to heavily invested in AWS to consider an infrastructure shift at this point