Treadmills
Traditionally I am not a fan of the treadmill habit. The treadmill has a tendency to make one feel like a hamster stuck inside a wheel. It also provides you with the privilege of being able to stop and let your mileage increase while you rest. I also think the treadmill encourages shin splints, but that's a personal experience.
However, when the weather is not its finest and you just can't deal with that crisp, chilly, "spring" wind (I will go to my grave hating wind), or perhaps there's a PGA tour event on the tele, the treadmill is not a bad place to crank out some mileage.
And here's one thing I do admire about treadmill runs. If you are consistent about making yourself stay the course, or mill, then this is an excellent spot to improve your pace. You can select just how fast you want your run to be and work to manage it because the treadmill doesn't slow up and down on its own like you would running on the road. Sure you can adjust the speed with these guys +,-. But let's be committed here.
I also like that if you have access to a treadmill, you don't have access to weather induced excuses. The "it's too cold outside, I'll wait till tomorrow" trick is out the window. So here's to making runs work where and when you can! Treadmill, track or road. Happy treading!