In a curious twist, it looks like Google+ currently causes more trouble for Google than it's worth it. I have no doubt that the problems will be solved soon (if nothing else succeeds - they can always throw more hardware at it), but it's instructive to say the least.
As I'm writing this, all non-search services of Google I've tried are broken to a greater or smaller extent, starting with Google+.
I suspect this is because Google+ presents a fundamentally different type of server load than Google's other services. While others are definitely read-mostly to a large extent, the social network is very transactional - people write things all the time. This cannot be handled by map-reduce :)
While other Google's services are also user-modifiable - Mail, Docs, even Buzz, it looks kind of like they were not ready for the torrent of small transactions coming in. This is not search. This is more like Twitter processing than bulk read-only queries.
Of course, Google being what it is, it will no doubt be fixed soon.