Ok, so I use my Droid for my corporate email and calendar as well as personal use. I agree with what everyone had said about the default email app's handling of exchange: it's sorely lacking.
So I tried Touchdown. First off, it has good features (at least the ones I need), seems laid out ok from a ui/menu perspective and is reliable. Two things though turned me off. First is the cost. Ouch that thing is expensive but I suppose you are paying for features not found all in one place in any other app. Two is the UI. Come on guys, for that amount of cash at least make a small attempt at a UI. I mean really! Believe it or not in the end, I had to quit using Touchdown because I couldn't abide the UI. Let's not even mention the garish looking widget! Yes call me stupid or whatever but the UI is important to me especially when paying that kind of cash.
So I searched and came across Moxier. My first thought? Holy crap its more expensive than Touchdown! I looked around, read some reviews, researched and it seemed to have what I wanted, including the UI. I bit the bullet and bought it figuring I have a 24 hour return period. All I can say is, yes! I'm very happy so far. Set up is just as easy, stability is good, features I need are there and they work (GAL lookup for example). Best of all is the UI. It looks like it's built for a Droid. It's sleek and laid out well and the widget is functional and informative.
So I know it is kind of weird reading this and thinking that I put most of my criteria on the UI, but, in reality the two apps were close enough in features that that's what it came down to.
So if you are looking at an exchange client and have looked at Touchdown, you may want to look at Moxier as well. True, there is no trial period but if you're diligent about your 24 hour return policy then you shouldn't have a problem if you hate it.
Not really a review but just wanted to shared some experiences.