Hey Logan,
I used to use Dreamweaver MX studio - but it was too design-"Y" for my liking - GUI editors etc.
From a purely PHP perspective I found Zend Studio does everything I need. Mounting FTP sites, including them in projects, inspecting all php files into the project. I run remotely all the time - so I use the remote degbugging with the Server and its just soo sweet.
It has code completion and incluides the PHP manual (if you want it to) which then given you all the function definitions real-time as you type.
I understand what you mean about it being slow on startup - im running on XP pro - with 256mb of 1gb RAM assigned to my JVM - this is more than enough - it flies when its open - i think its just the overhead of using microsoft as an OS running a JVM - (Im sure theyve added some slowdown somewhere - Oops - that's slanderous) when I run it on a linux install - it flies.
This I guess is very much personal prefernce - but Vs older incarnations of the same product it has come along way - and beats the pants off phpEdit .
(oww.. also has a great webservices modules that will create you WSDLs for you ).!!
Never tried PHP Designer 2005 - my have to give it a spin!
Any one else with any input?