Besides time itself of course!

I read that many people dont get past 128 time compression.
Why's that? It took me ages to get from France to US coast before i installed SH3Cmdr, how could someone do it in 128TC?
I've noticed that the weather gets as bad as heck when i sail for a day or two in 4k TC but it turns good if i sail on low TC for some hours.
Anything else?