Fresh Air Exchangers

Is anyone using one of these air exchangers at their home?  I know a lot of newer homes are installing them right away because of code reasons.  I have an older home and was thinking of installing one of the basic systems that draws in outside air based on indoor relative humidity, outdoor temps and personal settings of how long you want the system to run.  I watched a few videos and the system I am looking at is a cheaper option but they recommend it over some of the others.  
I am just not sure if it is really worth it so I want to see if anyone has looked in to these systems or has one.  
Here is the system  Aprilaire 8126