I was using Dreamweaver for about six years for web work (even back when it was owned by Macromedia, remember them?). I'm very resistant to change but figured I should branch out and explore my horizons; surely there was something better out there.
My biggest hitch though was I wanted to be able to control the syntax highlighting. While I was looking for a newer/better/whatever IDE/editor, I had gotten very used to the way Dreamweaver coloured its syntax. I tried the following editors/IDEs:
Notepad++
InType
Notepad2
Aptana
Eclipse
Geany
Komodo Edit
A tried Notepad++ because I heard a lot about it and I knew a friend who used it to write some C code, but really I thought it was pretty subpar. It randomly highlighted certain functions but others it didn't. You could add them but who really wants to sit there and add functions/identifiers? Plus there was no difference in the colours between identifiers and something like language constructs.
The others were decent (except Notepad2, just wasn't for me) but didn't work for me in one category or another, except Komodo Edit. It did everything I wanted plus had a ton of other features that have proven to be very useful over the last 6 months or so (I forget exactly when I switched). I was convinced in 15 minutes. I've wanted to try phpDesigner but just haven't gotten around to it.
To answer the question I was "converted" within a few days. There were a few things I had to get used to but now I don't even remember the way Dreamweaver did them.