I may be biased, since I go to UMD, College Park. Right now, I am a junior, pursuing a physics/astronomy double major. At UMD, physics and astronomy are very close, there are only 6 additional required classes for the double major.
I think it is a great school for physics. I think the physics department has over 70 tenured faculty members, and the astronomy department has about 30 teaching faculty. From the outset, undergraduate research is highly encouraged, and with so many researchers in both departments, chances are there will be something interesting going on. Professors are readily available to talk, and most of them seem to enjoy talking to undergraduates. The classes taken by majors are generally well taught and challenging.
It is not perfect, though. I would like to see a fluid mechanics class offered, and I certainly would like to see more emphasis on numerical analysis and maybe even programming in the sciences. The class sizes are fairly large, even for majors. Physics majors have a series of introductory classes separate from the engineering/other majors' physics classes. But we still routinely get classes of 40 students, even in senior level classes. But, as I stated before, the professors are very available.
We see a fair number of transfer students at College Park, too. Howard Community College and Montgomery College are both pretty much next door and are fantastic schools. These transfer students are generally successful at UMD.
I am just about to start working with the Space and Plasma Physics group in the astronomy department (UMD is tied for the #2 ranking for plasma physics), and this will be my first research experience. However, I know many students who have been involved in research since their freshman year.
I would recommend for you to poke around the department websites:
http://www.astro.umd.edu/
http://umdphysics.umd.edu/
I know that UMBC has a solid physics department, but they do not receive as much support as College Park. Sorry I can't be of more use for UMBC. If you have more questions about UMD, feel free to ask.