The pro is it comes with mounting screws and holds the 2.5" drive.
But the design is not well thought out and mounts the drive too deep into the case. If I'm adapting a 2.5" drive to fit in a 3.5" drive space then the mount should mimic a 3.5 " drive. In other words, when mounted in the adapter the 2.5" drive is centered. Since the 2.5' drive is physically shorter than a 3.5 inch drive it makes the cabling hard to route. If you picture most factory built computers, the power cable ends are daisy chained and short between two stacked drives. When the drives are all identical the power cable neatly connects vertically down the row from drive to drive with very little if any slop or slack. Now try to use this adapter to put a 2.5" drive in line with other existing 3.5" drives and the power cable had to somehow bend horizontally into hole where the 2.5" drive is in order to connect to power. Then it has to bend back out to try to reach the next 3.5" drive and the distance between the connectors is just too short. All the designer of this adapter had to do was design the adapter so the 2.5" power and SATA cables are vertically aligned with where they would be if it was a 3.5" drive.