I just liked the feel of BBsmart better. The options were easier to setup and more simplified. I guess it was mostly because I had used it a while before Empower so I was more used to it. Empower is great, don't get me wrong, but I would try out the trial and see what you think about it - don't base your own opinion off others.
If you are considering Empower, don't forget to install the latest trial version of Empower Pro 3.0. It is considerably quicker than the older version, and has more integration. A large difference between Empower and BBSmart was always the price. Not sure how much the new Empower is, because I was able to upgrade for $5. I have used Empowerfor months now and I'm very happy with it; especially their recent upgraded version. Take them both (BBSmart and Empower Pro) for a trial run, and draw your own conclusions.
Posted from my CrackBerry at wapforums.crackberry.com
Acutally you can have both installed on the BB at the same time, you just need to have one or the other disabled, so only one is running to catch your email as you open it.
The way you have both on is that in BBsmart options either check if you want it to be your default or not, if not, then uncheck it and then empower will take over.