I can't begin to tell you how wonderful it feels to get back into the swing of things. Wonderful, and at the same time, incredibly frustrating. For me, the difficult thing about a return to "normal" is that it takes a while to figure out just exactly where you're at. In other words, I have to disregard what I was lifting prior to my break, how far I was running (as well as how fast and how often) and how quickly I was ramping up (both the weights and the distance/speed/frequency). It's almost as though I spend a week or so testing the waters - keep going until I can't go any more, see how I recover, and build a training program based on what is inarguably purely subjective data points.
So while on one hand I feel productive again, on the other I'm not really accomplishing much in terms of building strength or endurance. But it's important to remember that there is no alternative (other than never taking a break in the first place, of course). Were I to disregard the basic fact that I had lost fitness over the past few weeks and jump right back in where I'd left off, the only thing I'd take away from my training would be an injury.
In my book, slow and smart trumps speed and stupidity every time. Just read Aesop's The Tortoise and The Hare :)