I agree with Harry and the others. I would definitely take the lucid abilities. Imagine, being able to live in another world for like 2 years and only 1 second has passed in Earth time. You could do WHATEVER you want, even win a MILLION DOLLARS in your dream, and have sex with the most beautiful women, fly, have shared dreams with friends, be chased by dinosaurs, have conversations with God or Doc Brown, ANYTHING!