The size is nearly the same:
11.3 x 7.5 x 2.0
versus
12.1 x 7.7 x 1.8

So: still I'm looking for relevant differences between the 7230 and the 7730

Do you remember in which details the keyboards differ?

Does anyone know, if the declaration of the standby time of the 6280/6230 with 16days is true or not?

Thanks.