I have to say, if you've got a bike, computer or ipad, a trainer, and some sort of speed, and cadence sensor, you owe it to yourself to download zwift for you indoor trainer rides.
I've got about the most basic setup you can have, a "dumb" trainer - Cycleops Fluid2, then an usb extension cord with the Ant+ dongle on the end to my laptop. You want one that's USB2. And then all you need are the sensors, not even the bike computer. I think there's also bluetooth sensors, maybe by Wahoo, but I don't know how those work.
From there the info those transmit, goes into Zwift where you put your age, height, weight, and it calculates your power. Everything on zwift is based off power. The neatest thing it does is compensates for drafting, and changing elevations. Granted with a dumb trainer you're still pedaling the same, but on the screen, everything you see reflects what it's calculating, and everyone around you is doing somewhat the same. So climbing a hill is still an rear end whipper. Like you can see here in the top right this is down hill at a -4% grade, so we're getting it pretty good, maybe a little too good but thats alright.
So with that, if you just want to rack up miles, you probably don't want to do it on Zwift since I know pedaling at 75ish RPM's on the big ring, and any of the 4 smaller cogs on the rear I should be going over 20mph. On Zwift, climbing up steep hills, it calculates to watts, so you may only go 10mph, but the inverse is on big descents, you haul.
All in all, I'm a fan. I'm still on the free trial, but I'm going to subscribe once its up. I did order a trainer tire after getting in on a race last weekend and putting a flat spot on my good tires.
Another neat feature is if you want to do a group ride, race or workout, just join one of the rides on the events page. There's nearly something starting every 10 minutes, 24 hours a day.