We decided to downsize to a TH Condo because we made the final decision to stay in our major metropolitan area since my wife has 9 specialists and it was too much hassle to try and reestablish that infrastructure in another more rural/less expensive area.
We went from a 2,700 sf to 1,500 3bd 2 story and still have one daughter living with us while going to college. We got an end unit, but they are piggybacking so I also have someone above me.
Plusses:
I got rid of so much stuff - 18 SUV trips to good will and a 15' truck from the got junk people. I checked and had no hidden treasures, so it was just easier to get rid of things than try and resell them. Definitely glad to get this done instead of waiting until I was 70+. Wore me ragged at 56
Easier to clean, no outdoor maintenance, 5 minute walk to a grocery store and 7 decent restaurants. Location is also close to a main road, so saves me 10 minutes every time I go somewhere. Laundry and bedrooms are on the same floor so big improvement over Bedrooms to basement in old place. Also only need 1 stair lift for the house instead of 2.
Negatives:
Neighbor noise - Not constant but not zero either. I hear their garage door when it opens for example. Probably the biggest adjustment after SFH, but it is what it is. We use air purifiers so have white noise but probably irritating to me about 5% of the time. Hard to avoid in multi family living.
No backyard to throw the dog into. You might be able to avoid this if you can put up a fence around your townhouse back yard. Condo does not allow so I have to walk the dog instead of just letting them into the fenced backyard if I am busy/tired.
1 car garage - plus and minus. Never had a garage before, just a carport, so I like it. However, my SUV would not fit in a 20' garage so I had to sell it and get something smaller. Cheaper for sure on gas, insurance, and maintenance.
Space feels a little tight. I have a home office set up, but wife would like a craft room but that is daughters space for now. Still have room for babysitting grandson and entertaining, but just not like before. Can't have a grill on my balcony for example. No propane allowed. I could use electric, but just got an air fryer for grilling stuff. Otherwise the space is fine and the 2 floors give good separation of living/sleeping.
All in all I am less stressed without having to worry about cutting the grass, outside repairs, etc. and I love the location.