If your personal focus is on research then there are a number of "cons". First, since the place is small, there is less opportunity for local collaboration. Then, both the teaching load and the expectations for what you do make any research more difficult except in a few areas. You will find external funding harder to get most likely and less opportunity to use it effectively. On the other hand, any research that you get published might give you a boost locally. A 60/20/20 balance in expectations for teaching/service/research leaves little time or energy for serious research. And even the "research" portion might be more "keeping up with the field" than it is "advancing knowledge".
If your personal focus is on teaching and living in an environment rich in ideas then there are few "cons", though the pay may be lower. I went to an undergraduate place where the graduate program was nearly invisible and non-existent in my field (math). I had a lot of teachers (not all) who were very interested in my progress, not their own. They didn't publish much, but had an excellent grasp of what an undergraduate in math needed to know and for most of them, how to impart the knowledge. They helped us get insight into the field. IIRC we were only three graduates in math in our class. All of us got doctorates from good schools. One of us returned as department head after working elsewhere for a while.
If classes are small then student/faculty interaction is natural, though not every place can make that happen.
Moreover, faculty at such places have an opportunity to interact with faculty from other disciplines, which can be a plus for a "well rounded" person. The "college" system at Cambridge, for example is another way to enable this and make it natural. After dinner "sherry" hour, for example.
There was a lot of opportunity for interaction with the faculty at such a place and most of them were more than happy to oblige. It was, in fact, a community of scholars and their mentors. So, the rewards are mostly personal at such places.
It is also possible that your institution has the objective of "moving up" in the world. You might get an opportunity to design and teach in a graduate program.
But my experience both as student and faculty was that you could have a "balanced" life. That can be worth a lot to some.