saying nice to finally meet you in cantonese I have seen 聞名不如見面 to mean 'nice to finally meet you', but am I correct to feel that this is too formal, or still colloquial?
How else do you see 'nice to finally meet you' in an informal environment?
聞名不如見面 is a comment. It means &quot;better to see it in person than belief hearsay&quot;.
Example:

&quot;I have heard a lot about Paris, now I am here, it really is 聞名不如見面&quot; (implies the actual place is not what you expected, maybe better, maybe worse, maybe totally different)

If you use this comment as a greeting, you should also state what good thing about that person you've just found out upon meeting him
A polite way to say 'nice to finally meet you' in Chinese is '久仰'
Example:

「陳老師， (初次見面)，久仰，久仰！」- &quot;Master Chen, (first time we meet,) I have always admired you!&quot;

You can skip 初次見面 because 久仰 already indicated you have only been hearing about him but had not met him before
久仰大名 (long time admiring your fame) is a polite way to say &quot;hearing a lot about you for a long time&quot;
幸會 (it is a fortunate meet) is also a polite way to say the same thing, but not as humble as 久仰
Example:

「陳老師，(初次見面)，幸會，幸會！」

Another polite way to say &quot;nice to finally meet you&quot; in Cantonese is to  &quot;「好榮幸，終於同你見面！」 (It is an honor to finally meet with you)
If you don't want to be too formal, you can say:「真係好高興，終於同你見面！」(glad to finally meet you)