Build quality of both bikes is good.
Honda CG Dream 125 is good for the sound and its acceleration on straight roads. Its stupid vibration makes you sick. Grip of handle is hard and a little uncomfortable. It thrilling sound instigates you to drive fast and I mean fast. Seat for the pillion rider becomes uncomfortable after riding for 5-10 minutes. If you love Honda bikes CG Dream is a good choice. I still like it very much but I have to sell it
Yamaha YBR 125 very quiet on road. Acceleration seems to be less than Honda but I felt some torque in it. There is no vibration while driving. Its road grip, handling and stability is far better than Honda. Seat for both riders is comfortable. Makes you enjoy the drive rather than accelerating only. Headlight is very bright and really illuminates the road. I am in love with it.