New stuff is mostly additions rather than new ways of doing things; and I don't think any of the old ways have actually been discarded (which I would say is to their detriment, especially in terms of moldy old code; but alas..).
I picked it up pretty well in a month or two, which is about how much time you'll spend with anything, getting used to it. Directed lessons could prove more productive than pissing around (I, too, have been using it for years, and am still finding new ways of doing things), but in the grand scheme of productivity, if you're simply good at it and committed to excellence, I don't think you'll have any problems. (My assertion on that is: I've seen others working before, and they are *slow*. But they're still considered valuable enough by management to do the work. So if you're going slow getting used to it, you're probably at least keeping up with the average user. An expert is probably two or three times more productive than average, so remember that added value, too.)
Tim