Well Synology is doing something right as this is the third unit I now own. Easy to set up, quick transfers, can set the fan to be very quiet although mine lives in a spare room.
Some people will find the lack of front loading drives a downside, to be honest if I want to swap a drive it's not a massive hassle to power it down and pop the top off.
Loaded it up with some Toshiba N300 6TB NAS drives. Seems happy so far.