(If their neworks/servers are fast to west coast, imagine how fast they are to the east coast where they are located. They are even faster than my local home town ISP located in Oregon!)
As for servers, I used to have a shared hosting account. I had eight web sites, but the machine (dual 700mhz, 1 gig RAM, IDE disks) I was on probably had 100 sites total. There wasn't much reserve capacity, and the performance wasn't great. I entered a "co-op" deal with a few other sites on a dedicated server of our own. The sites now scream (64 bit operating system), have reserve to handle even a Slashdot link, and the cost wasn't much more than I had been paying on a shared plan.
If you're looking at buying a server, I strongly recommend going 64 bit AMD Opteron over Intel. LInux, Apache, and MySQL performance is smoking on AMD.