Hi Kev,
I use HoldemManager for my HUD. I have used poker tracker in the past, but prefer HoldemManager for ease of use.
I primarily use it for trends on certain players and gives me extra info to help me to decide in tricky spots. I use it for SNG"s, MTT"s and cash. I choose my own display and pretty much have decided what stats are strategically important for me to have on the HUD. There are some good YouTube vids discussing setting up and using a HUD.
I don"t really use it at all for analysing my own play, but sure there are some on here who do and can advise.