Guys I think you will find that any hidden text or extremly small text is indeed frowned upon by Google and most other search engines.
As for the power of a H1, the H1 tag actually attracts less value than bold text these days & it would appear from what I have read, that it has been devalued due to abuse by spammers. The H2 & H3 tags actually attract far greater value in terms of SEO. If you do a search for "SEO Pitfall" the guy that runs that blog did a very good article based on tests he had personally carried out. It is well worth reading. ;-)