Most of the time I use a desktop application called Gwibber to read twitter and to send the occasional twits. On average I usually send 5-10 twits a day. There are those exceptional instances when I have to search for particular twits, read them and then send 5 times the normal average number of twits. When these exceptional times happen I switch to the official twitter client which is their website, which means I’m going to the browser.
Most of the keyboard shortcuts in twitter don’t work in Firefox or it is terribly clumsy. I use Chromium or Google Chrome for this. The twitter shortcuts work uniformly in Chrome and the speed of Chrome makes it a no brainer to use.