The 96433899 and the UP10-16 are pretty much identical, except that the latter is $30 cheaper. That is the one I’ve linked to below.
Based on other reviewers, this is the quietest system on the market. This unit does not come with a check valve but one can be acquired on amazon for $50 or less.
Ratings: It has 4.4/5 stars on Amazon with 24 reviews. This is a solid product with many people backing its effectiveness. Click Here to Read the Amazon Reviews.
Timer: This system has a timer which means that you can set it to turn on for just the hours you’re home. For example, instead of leaving it running 24 hours a day, you may want to have it turn on the hour before you wake up and a few hours around the time you get home. That way you’ll get hot water to wash you face and hands and in the shower.
Quality: Comes with a 2 year warranty (from date of installation).
Price: View current price on Amazon. This is on the higher end of the scale.
Installation: 1 Hour installation at most. Very simple project that even beginner DIYers will have no problem with. This is a Water Heater Installed Recirculator (which you can read more about Here) meaning that the main pump needs to be installed at the water heater and the valve needs to be installed below the faucet of the sink furthest away from the heater.