I tried to do a direct comparison for the power usage but it was too difficult. The dryer seemed to draw a lot of amps to get the heating element hot then power down and cycle on and off again throughout. I didn't have a meter that could easily track the power usage for the dryer. 

As far as time to dry, I treat drying a little differently in my situation. I try to keep the dryer running continuously throughout the day as I do laundry. So as soon as the washer is done, hopefully the dryer is done too. That way I can keep feeding the dryer. 

All in all, I've been very impressed with how well it works for how cheap/simple it was to modify the dryer. 

If you have a miner sitting around, not hashing, why not find a way to put it to work?