Arfur (atys)
I turn off Microveg when there are more than 2-3 players around otherwise I get lag - not PWs, not rubberbanding but juddery video. It is clear to me that this is a bandwidth issue.
I turn sound off before I TP or go through a portal. With sound on, I crash out about 60-70% of the time. With sound off I NEVER crash out. Again, very clear.
I play on a Mac with the latest OS - several upgrades of the OS have not changed these issues.
I play under Win7 and haven't had the same issues with crashing on TP-ing or portals. It's only when running into Zora that I have about a 5% chance of crashing. Most of the people I know who crash in Zora almost every time are running Linux. That's why I'm leaning towards the Windows client being more different from the *NIX-oid clients than just the normal differences you'd expect from a cross-platform port.
As for the other, it sounds to me like the bandwidth issue is in your GPU. Aside from the top 27" models, the GPUs in Macs are less powerful than my GTX465, often far less. I had the juddery video issue on my Toshiba laptop and an old Pentium 4 as well, but I expected it as their GPUs are not even one-twentieth what my main system packs. Rendering all the polygons of other homins may just be too much for your GPU to keep up with, leading to framerates plummeting.