What I've found in aggregate is that GCE is a bit easier to use at first as AWS has a LOT of features and terminology to learn. When it comes down to it though, many GCE services felt really immature, particularly their CloudSQL offering.
One client recently moved from GCE to AWS simply because their CloudSQL (Fully replicated with fail-over setup according to GCE recommendations) kept randomly dying for several minutes at a time. After a LOT of back and forth Google finally admitted that they had updated the replica and the master at the same time, so when it failed over the replica was also down.
There were other instances of unexplained downtime that were never adequately explained, but overall that experience was enough for me (And the client) to totally lose faith in the GCE teams competence. Even getting a serious investigation into intermittent downtime and an explanation took over a month. By that time our migration to AWS was in progress.
GCE never did explain why they would choose to apply updates to replica + master SQL at the same time and as far as I know they are still doing this. I asked if we could at least be notified of update events, was told that's not possible.
There were other issues as well that taken together just made GCE seem amateurish. I'm sure as they mature a bit things will get better, and it is cheaper which is why I wouldn't necessarily recommend against them for startups just getting going today. By the time you are really scaling it's like they'll have more of the kinks worked out.