I hate trying to import Excel into SQL Server, for the reasons already stated, this is yet another area where MS does it so badly.
ACE really needs an option like IMEX to tell ACE to retrieve data as text with no formatting or conversion.
Fortunately at the moment my spreadsheets have standard layouts and no mixed data columns.
I have an old VB6 app that I wrote that extracted the first sheet as a text file with no formatting or conversion and then I would import the text file.