@John Gaber Welcome to BP!
I am a buy and hold investor of single family homes. I like these because they are relatively easy for me to manage while having a full time job. I buy in good school districts and for the most part I get long term tenants. I have been lucky and my tenants take have taken care of the houses (screen screen screen!). I also like single family because there is a bigger market for buyers if I ever get in a jam and need to sell. The big downside to SFR is if you do not have it rented you are on the hook for the full mortgage payment while a muli unit if you have one unit unrented you still have the other units bringing in money taking care of part or all of the mortgage.
I personally do not have an interest in 2-4 units because I do not want to have to manage issues between tenants (ie noise complaints), traditionally you have a higher turnover rate, and I don't want to have to worry about the lawn or plowing the driveway. I am however looking to buy a larger multi unit (around 10 units) and have a property management company run it but I am still learning more about the process.
Best of luck!