University class sizes and modes of teaching

Because I want to try out some techniques for improving things in the classroom I would like to know how the class size forces a particular mode of teaching. I suspect its subject dependent, may be age dependent, a perhaps culturally too. I'd really like to hear your experiences if I may.
No matter what I had planned, if the class size is very different then I have to teach differently:
1) I have to use “tutorial” type methods for up to ~12 students. Discussion round a table, a lot of individual student involvement.

2) “teaching” : 12-40/50. More of an address from the teacher, but easily able to tailor speed, content, examples according to apparent student involvement. Easy to set up dialog, get student involvement, do small group work.

3) “lecturing”: 40/50-100/120. preferable to have a prepared talk. Too many students to do much tailoring of delivery or content. Some group work may be possible at lower end of scale. Its still possible for students to ask questions, have teacher-student and student-student dialogue.

4) “large group lecturing” above around 120. Needs a prepared talk, can’t assess apparent student involvement to tailor delivery or content at all. Can take questions, but lecturer will have to repeat them so whole body can hear. No dialogue between students possible. Group work impossible.

Or does this categorisation just reflect my limitations?