In the context of a different question, we encountered a deployment performance degradation on EU5 of between 6000% to 10000% using Metadata-API. This means that work (saving a single APEX file to the server) done usually in 14 seconds took between 950 and 1500 seconds. This situation persisted for some days during the last week and as a result our development work came to an halt for a couple of days.
I guess the entire EU5-Pod was affected for this period, since I was able to perfectly reproduce it on two production Orgs and a couple of developer Orgs. Also other users reported it later, too.
My understanding is, that issues will be reflected transparently at trust.salesforce.com - only that seems not to happen always:
When I can't see an issue there, next thing I do is to feel responsible myself checking for possible reasons on my end (like bad test-classes, bad setup, etc). After investing some hours, it became clear the server caused the situation since others reported the same problem (here and on twitter).
I would be interested what kind of issues or which severity are we supposed to see at trust.salesforce.com and in contrast which issues we should expect not to see there? I found no documentation about it.
As something similar happened in March 2015 for CS14 I assume that everything development-related is unlikely to be shown. This is sad twice, since we have no chance to interact with the Salesforce support nor even to report those kind of issues.
To fire always the known support-communication substitutes like twitter to check if it's already on the radar at Salesforce is time consuming and not very productive. Also it's not very nice and I feel unhappy about my own complaints - even if they might be justified in the end.
So I would like to learn how you deal with such situations and how I might handle it better next time.