I'm originally from Obion county, and lived in UC for the first 18 years of my life. The whole damn county is small town. Even Union City is small town, I think the population is like 18,000 right now.
Obion is very small, there is nothing to do there, and the county schools are very overcrowded.
If you have children, I would suggest Union City, simply for the schools. Housing costs are low, there are a couple of bars, and you aren't far from the major highways. I-69 is supposed to start being built in the area in about 2 years. Its taking my fathers buisness, so I know a little more about it.
Let me know if you have any questions, I grew up all over NW TN. Troy, Obion, Hornbeck, UC, Tiptonville, and Samburg I know like the back of my hand. I love the area, might move back there in about 30 years, but for now I'm happy to just visit twice a year.
