When I switched to Mac, I decided I didn't want to go half way, but would try to go all the way. Of course it's not that easy: I had something like 15 years using windows so shortcuts, and functionalities, and navigation through MS tools was something I had learnt so much that just thinking on using another software was scary.
But then I bought my Mac Book air and it came with Apple Email. Ok, it's not Outlook, I have to recognize that, but it does the same things and it doesn't crash as often. One of the facts that made more sense to me is the way it compresses data. My last pst file in Outlook was about 10 GBs, but when I looked at the same folder structure in Apple email, it's around 6 GBs right now. Haven't really looked into it, but it's nice to know that it's saving some space for me!
Well, I still need to get used to finding some stuff through the program. I still don't want to use outlook, but I have to admit it's interface is more comfortable for me, coming from a Windows world. I would say the interface in Apple mail could look a little bit more like outlook and that would improve adoption rates by a lot for guys switching like I did.
If you haven't use a mac yet, this program helps you get used to it as email is the one thing we use more than a browser these days.