What exactly do you consider slow? Most recently I was getting a consistent 500kB/s downstream on my laptop [edit: while grabbing some rather large PDFs, so continuous downloading]. I've yet to give it a go on iOS.
Perhaps it's gotten better lately, but I found browsing with Tor last time I did it to be painfully slow, with some pages taking forever to load. Didn't run a speedtest, though.
In general, your experience with Tor/Onion routing, will be wholly dependent upon the path setup for your requests. I've been using Tor on and off for years, sometimes experiences are good, sometimes they aren't.
If you are looking for a general approach to obscure your browsing from an employer's network, but don't need the whole feature set of Tor, you are better off setting up a proxy to a remote machine. If you truly need the greater anonymizing of Tor and are willing to take possible latency / speed impacts, do so. Just don't expect it to be optimal for the first case when doing general browsing.
It is great to see the Onion Browser available so readily/easily.
