Mike, it has been a while since I switched to the saddle but here is the best advice I can give you.
1. Practice, practice, practice. It is going to take some time to get used to it because it is different than anything you've ever done. Practice at ground level as much as you can to get used to it and comfortable.
2. Practice shooting from the saddle in the tree. Again this is a bit different that what you are used to, but once you get used to it I think I can shoot more accurate from a saddle than a tree stand due to having more stability. If set up properly you should be able to move around and shoot 360 degrees.
3. Don't give up! You may get frustrated at the beginning and feel like its not for you. This is the most common thing we hear. Most likely, it WILL take you some time to get comfortable and used to it in hunting situations. Practice in the yard is still different than a 3 or 4 hour sit in the tree where you're not moving much. I would say it could take up to 10 sits to start to really get the hang of it.
4. Prep as many trees as you can this winter and spring! You will thank me next fall! I love having the ability to be mobile and go where I want, but there is nothing like walking to a tree I have already set up, climbing up and strapping in.