How does a 1 yr. Visiting Assistant Professor (in physics) position look to a small liberals arts college
I'm in applied mathematics, at a school that you would probably describe as "R2" (the old Carnegie classification system has been replaced by a newer system that no longer uses terms like "R1".)  In my department, that year of experience as a VAP would make you a more attractive candidate, since you don't currently have enough teaching experience to be a very strong candidate.  

It would also be helpful just in terms of your having a broader range of experience in higher education- many candidates that we talk to simply have no idea what it would be like to be a faculty member at our institution and have unreasonable expectations.