The Chamberlain B550 is another good choice for D-I-Y installations, and can even still be a good deal when professionally installed. If you have a normal steel or wood door that is properly balanced and working smoothly, this is a good choice. It comes with two remote controls, a keypad, safety eyes, and a wall control.
While a belt drive like the B970 and B730, the B550 has a 1/2 h.p A/C motor. There is a little bit more vibration and noise, but it is still pretty darn quiet. Some of them start to make a slight squeaking sound as they get older, but most people aren’t bothered by it. It is a tried and true motor design that has been in wide use for about 20 years and has proven reliable. The rail system is the same square tube as on all Chamberlain openers.
The two features that it lacks are the battery backup and the fancy wall control with automatic close timer and motion sensor light activation.
Remember is that if you are replacing an existing LiftMaster, Chamberlain, or Craftsman opener, the B550 (or any other Chamberlain opener) should be able to utilize the same hangs and wiring, making for an easy installation.
In summary, I think this opener is a solid choice and, despite lacking some of the high end features, is a great value for most D-I-Y jobs, or even if you pay for a professional installation. However, if you are looking for the absolute quietest possible garage door opener, the B730 or B970 might be a better choice.