In the spirit of Scotty and Timmy among many others, I decided to try out these tools. Keep in mind these are my opinions, so I will qualify this once here so I don't have to keep doing that below. Also keep in mind (even when visiting the guys I linked too) that most of their comparisons are not with Resharper 1.5.
I started out with Resharper 1.5 and was impressed, although I am ashamed to say that I didn't use all the neat key combinations to aid me in my writing. I liked some of the optimizations and some of the color coding. I didn't like how long it took to load Visual Studio. For $99, I was still considering it.
After my free 30 days, I went to CodeRush 1.1. CodeRush was pretty, but I really, really hated it. It adds a lot of useless lines and animations that just distracted me with minimal aid. I landed out turning off each feature one by one, which negated any usefullness. One day I got really pissy because I wanted to name a TimeSpan “ts”, but it kept changing “ts” to some object or code construct. I know “ts” isn't descriptive, but sometimes if I don't care about something, I like to name things short. In CodeRush's defense, they have a TON of options. Personally, I think way too many. I couldn't possibly remember all those key combinations and ways of doing things. And for $250 there is no way I would buy it.
I then went to Visual Assist X 10.1 which was a total waste of time. I think all it did was color code everything in a way that made me think everything was either a comment or not used (since it uses light grey to show variables, and Resharper uses light gray to show unused variables). Don't quote me on what Assist makes light gray…I am guessing. All I know is a lot of it was light grey. If you have used Resharper or CodeRush, this seems pretty skimpy. For $99 it didn't hold a candle to Resharper. Whereas Coderush lasted about 10 days, this one lasted about 2.
All the while, Resharper's price was about to change to $149 this past April 5. So I bought it, and very glad I did.
When I reinstalled it, I took some time to try to orient myself more around the tool so that it could help me more. That was when I truly found the program to be indispensable.