It's just slow

Ty all for your replies (I love this community, everyone is friendly and helpful).  Answering some questions: -

Network infracture

According to our network side, there is nothing special - no outbound proxy getting in the way.

Where are we

Region is Europe

Navigation

Yes we are using structered NAV, in two site collections.  Yes, one does have alot of sites and it is expected that when on the home page, it will take a while to load the navigation.  In our other site collection we only have 5 sub-sites, minimal navigation - and this is slow as well.

This week things have speed up, which is a good thing. Maybe MS were deploying updates that were slowing us down.  I will keep montoring it and see if speed stabilises.