In the old editor you could select different fonts and sizes for text and that was very buggy. First time it worked, second edit you suddenly had one text in 10pt and another text in 8pt size and no option to correct that other than the html editor.
Also from a formatting point of view I find having block types only better, paragraph, preformatted, heading 1,...
Getting rid of the old formatting is no problem either, there is a clear-formatting function in the editor.
Would be nice however if all the inline <font> tags could be removed automatically during the migration.
Example from my blog (in text mode):
<span style="font-family: 'courier new', courier;">insert into "D050767::Customer.VT_""dbo"".""address_input"""</span>
In the new editor I would either use the source code button or the preformatted tag instead
<pre>insert into "D050767::Customer.VT_""dbo"".""address_input"""</pre>
But I am not sure if that really is a good idea or not because of what others did.