It depends a lot on the field. At my community college, the STEM classes had standards. Totally incompetent people disappeared after a semester or two of going up the coursework chain. Meanwhile, the liberal arts professors had to deal with people that couldn't write a coherent sentence if their life depended on it, even in advanced classes. However, I constantly read similarly demented and completely mangled english sentences written by graduates of the local public four year university.
I can't really recommend community college for STEM, since at least in my original state, you had to start as a freshman at university even if you had an associate's degree in science that was "guaranteed" to transfer for credit. (The engineering department's justification was "we'll accept your credits, but you still have to take everything over again.") It's a good way to get screwed, and community colleges offer very few second year science and math classes. (The liberal arts people had much less difficulty transferring.)
However, I did learn my calculus and sciences very well because I had excellent teachers that I could ask questions of if I needed to. My physics professor had been teaching for over four decades--and with a small class size of around ~20, I had plenty of opportunity to absorb the material and understand it completely. As a result, I now find myself tutoring my buddy at a $60,000/year private tech college, because my knowledge of the subjects is sound and the quality of the teaching at his school is completely terrible. Interestingly, the homework assignments and test questions are near identical in terms of subject matter covered and difficulty--the main difference is that the private tech college curves, which my professors at my community college were explicitly forbidden from doing.
In my state the universities must accept equivalent course credit from in-system community colleges. And within my own city it's widely accepted that 1st and 2nd year calculus classes at community college will have vastly better quality of teaching than you'd get taking them at the 4 year. (This reputation doesn't apply to other subjects.)
Makes it a lot easier to get personalized letters of recommendation, too. My first year science and math professors all remember me, since the class sizes were small and enthusiastic students are easily noticed. I doubt that would have been the case at a university, where I'd have been crammed in with several hundred people.
I can't really recommend community college for STEM, since at least in my original state, you had to start as a freshman at university even if you had an associate's degree in science that was "guaranteed" to transfer for credit. (The engineering department's justification was "we'll accept your credits, but you still have to take everything over again.") It's a good way to get screwed, and community colleges offer very few second year science and math classes. (The liberal arts people had much less difficulty transferring.)
However, I did learn my calculus and sciences very well because I had excellent teachers that I could ask questions of if I needed to. My physics professor had been teaching for over four decades--and with a small class size of around ~20, I had plenty of opportunity to absorb the material and understand it completely. As a result, I now find myself tutoring my buddy at a $60,000/year private tech college, because my knowledge of the subjects is sound and the quality of the teaching at his school is completely terrible. Interestingly, the homework assignments and test questions are near identical in terms of subject matter covered and difficulty--the main difference is that the private tech college curves, which my professors at my community college were explicitly forbidden from doing.