Originally Posted by hhnngg1

Once you start doing TrainerRoad, you will know the answer. It will dramatically improve the quality of your cycling training. It's very eye opening to get structured workouts with precise power levels tuned to your fitness level. It's so good that for actual training for improvement, I'm pretty sure I'm better served indoors with TR than riding outdoors with possibly the exception of uber-long multihour rides (and even those could likely be greatly shortened by doing in structured on TR.)

Trainers can be harder if you're used to coasting and downhills outdoors, but can also be easier due to lack of climbs. Lack of wind cooling is also a real factor - get a huge fan.

EDIT - if you really want to get the most out of TR, you probably will want to upgrade to a Kurt Kinetic since the power readings are more precise and accurate. But try it out with your cheap trainer first to see if it's for you.