1) I have lived in London for 4 years (I have been living in London for 4 years)
2) I have worked here since 1990 (I have been working here since 1990)
example #1 from the video
Both are technically correct, but using present perfect continuous is arguably less ambiguous. It's a matter of preference, but I would suggest reducing ambiguity where doing so doesn't add complexity.
Why? Less ambiguity means less cognitive overhead, which is the primary reason most english communications specialists argue to favor simplicity.