Hey Link- Good questions, here goes:
1. Router Restart- Sort of, but it's not really a source of the problem because this is appearing on many different networks. Everything from work to home to coffee shops. We have fiber at the house level where I have it run into a cisco router. Thus, I'm quite certain its not a network issue.
2. Yup, should have mentioned this... I've tried Chrome and Firefox. Can't really say there's a huge difference because I've found both browsers faster anyway, but I aways prefered the security of Safari. Overall, the entire system just feels sluggish. But if I had to so, then Safari is definately the slowest of the browsers.
3. Other internet apps appear fine, but sort of hard to guage actual speed. Downloads in both the browser(s) and in the app store seem fine.
4. Well, yes, there are many other devices on the networks, but they have always been there.
5. See 1: Tested on many networks. All Feel much slower.
6. Great question: I have tested with Ethernet and yes, it also feels slower.
As an added note: The slowness is when the pages are first trying to load. It appears as though the browser/network stack is trying to resolve something. Once it actually starts loading, its fine. There is just a sort 'negotiation' lag with web pages. I've done speed tests and all my networks (note: ones I have control over: Work and Home) are pegged out at 15Gbps down. But... Its always the initial startup thats so slow. As a result, I decided to try different DNS providers. OpenDNS was the fastest at resolving names, but it wasn't enough to remove the difference.
Thanks!