I've been using a Harmony Hub and Companion remote for over a year and it greatly simplified our home theater setup. We went from 4 separate remotes (TV, cable box, receiver, Roku) to a single slim and simple remote that intelligently swaps button mappings automatically to control the devices we want based on what input we chose. It's very simple to set up through the smartphone app or on a computer and Logitech's database of devices it supports is absurdly large. You put in the model number of your device (TV, cable box, receiver, etc.) and it pulls in info about how many inputs/outputs it has, what channels your cable provider offers, and a ton of other information that seriously takes the headache out of setting up this sort of home theater automation.
t's easy to set up "activities" for things like "watch HBO" that allow you to turn on your TV and cable box (and receiver if you use one), select the appropriate inputs, and even change the channel all with just the press of a button. Use a Roku? How about a "watch Netflix" activity that turns on the TV and Roku and launches the Netflix channel. The hub remembers what devices are turned on and off and can switch activities on the fly, so you can go from Sunday Night Football to Netflix and chill and the hub will just switch inputs without needing to power-cycle the TV in between.
It also integrates with Google Home and Alexa, though I've only used Google Home. The basic integration with Google Home is clunky - "Hey Google, ask Harmony to watch TV". But with a little IFTTT magic you can set custom hotwords to trigger activities and even include custom responses from the Google Assistant. Suddenly, you're asking "Hey Google, turn on ESPN" and BAM! Google replies "Sure thing! Turning on ESPN" and your TV, cable box, and receiver click on and the channel number for ESPN gets typed in on the screen automatically to change the channel for you. You can also use the Google Assistant on and Android phone to control the hub by voice if you do not have a Google Home or Amazon Echo.
If you're looking to simplify your home theater setup for under $100 you cannot buy a better product. It works with newer devices over WiFi/Bluetooth and older devices with infrared blasters built into the hub (additional IR blasters can be plugged in to reach further away devices or devices in an enclose cabinet). If you're looking at this and hovering over that Join Drop button I would suggest also looking into getting a Companion remote to pair with this unit as this drop is for the hub alone which will need to be controlled through the app on a smartphone or using a smart assistant as outlined above. The Companion remote is usually $30 and works perfectly with this hub. An old Harmony Remote you might have lying around cannot be used to control this hub.