That's supposed to tell us what exactly? That under the most optimal technical environment "the network" can substain large blocks?
I'm shocked

Actually, no, they've been having huge problems with it; with nodes crashing all over the place and such. Of course: Bitcoin Core nodes on testnet are unaffected: They're just ignoring the XT chain entirely, banning those peers, and continuing on as if they didn't exist.
I'm a bit surprised to read this.
I'm not fond of Bitcoin XT & BIP101 but having being vocal about the lack of tests, I've decided to setup a XT node on a VPS for this test.
This node is pretty weak (1 vCore, 2Go RAM, windows as OS) but so far everything has been fine with no crash.
Anyway, it doesn't change my mind that BIP101 without prior works on the P2P protocol isn't a good idea.