Working just in code sounds a bit crazy because you have to keep stopping, load the page into a browser to see what it looks like so far.  So if a wywiwyg editor creates the code for you, then why do it by hand?  Because the code itself is very important, and in a wysiwyg editor it is out of your control - such editors are famous for creating lots of unnecessary stuff in your code, and being somewhat non-standard too.

On the other hand, if you use an editor that does both, you can flip between the two which can be the most productive way to work.

Here is a selection of web design programs that we personally have used much.  The pluses and minuses are both mentioned, so you can choose one that most suits your needs.

NVU.  An 'open-source' wysiwyg editor that also allows you to edit the code directly.  It has become very popular among web designers due to its ease of use (in most functions).  On the down side, some of its functions are in very strange places and take some finding, plus the resulting code often comes out with large gaps between the lines.  Also, there are some table handling operations missing.  NVU is still available but development on it stopped quite some time ago.  Not widely known is that it was developed further under the name 'Kompozer' which can be found if you search the internet, but although this has been described as 'NVU with bugs fixed' we found this to be not the case with the small problems we had.  Also there have been reports that Kompozer has accidentally introduced new bugs.  You can only tell by testing it out yourself.
http://www.nvu.com/

WebNamo.  We used version 4, but believe it is now up to version 6.  WebNamo was found to be the most well-behaved wysiwyg editor around.  It is not 'free' like NVU but does beat it in most aspects.  Includes a full professional site manager much better than NVU's simple one.  Being more professional than NVU it can seem more complicated, but you have to decide just how well you want to do the job.
http://www.namo.com/

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