do you have an opinion of them? Or A preference for one over the other?
Well, I have only used Litchi once or twice on my Android tablet but I have used AP much more on my iPad.
If you're asking about the difference between the two Litchi versions, then I think it comes down to the number of features you want to have, right out of the gate.
Do a versus Google search, you should come up with at least a few hits. But I'm pretty sure the difference in the versions is the number of included features.
Good luck with your choice.