I found this blog from your Firewalla post. It seems we had similar recent journeys related to home network upgrading, and considered many of the same options. Well, the few that existed a year ago, anyway. I feel like I could go on for days about this.
What's got my attention is your decision to go with the >1 Gb core networking. I keep looking at that stuff, finger hovering over the "buy it now" button, then back off. I keep thinking back to my first Gb switch purchase years ago. It represented a 10x speed boost for not much money, so an apparent great value. In reality, I don't do a lot of huge file transfers, so the value turned out to be less than I thought. In other words, worthy but not really a life changer it appeared to be at first.
That in mind, 2.5Gb is an even smaller bump in speed and 10Gb will require fiber and GBICs for longer runs and at least upgrading a bunch of patch cables to exploit (my home wiring is mostly cat-5e). At least that's my thought process every time I don't click on "buy." Well, that, and the hard ceiling of a 1 Gb max ISP uplink (I think mine is still 5-600 mbps for the same reason I haven't bought any super-fast switches). About the only thing beyond ordinary household networking I've seriously considered, is going to fiber between two of my switches on an 80' run. That's within the limits of cat-5, but fiber would remove all doubt for around $200 altogether. FYI my post on the Firewalla thread appears about 4-5 entries before yours, with a wooden rickshaw on top of the NAS.
I'm curious to hear how the > 1 Gb networking has improved things for you over 1 Gb. Maybe I missed it, but it seems you went to this straight from everything plugged into your ISP-supplied modem, which is probably 1 Gb on the wired side.
Which leads me to another topic: switch backbone capacity, and did that factor in to your hardware choices? For example, I've about bought my last Netgear unmanaged switch because of that. There might be 8 gigabit ports on it, but it will only move 1 gbps across them, and presumably why they're so cheap. I recently upgraded one of those to a Cisco SG110D-08 for about $80 and it brings 16 gbps backbone between its ports. It's probably confirmation bias on my part, but it did seem to improve response time between devices on that switch and the rest of the network. Or, it may just be doing a better job of throwing packets to my ancient USR core switch because it's Cisco LOL. Another unsolved mystery I probably won't dig any deeper on.
Anyway, just a few thoughts to ponder. Thanks for posting your stuff.