The HEM 2 (Notecaddy required) CoffeeHUD has a beta now. It should be at least as good as the PT4 version now. The full release on that beta will come in the next few weeks.

I would make the decision based on which tracking software you prefer, HEM 2 or PT4.

I've used both PT4 and HEM2 and prefer PT4 by quite a bit. Mostly it's personal preference though--they largely do the same things overall just sometimes in different ways. I know people who prefer HEM2 as well as some guys who have both. I think PT4 is considered the standard nowadays for HUSNGs though and is more prevalent, which can be a bonus since if you're studying with friends it will be easier to help each other.

That being said Ryan is spot on that if you're concerned about the CoffeeHUD don't be. Concern yourself more with picking the tracking software that seems best to you.