Nvidia AndroidWorks\GameWorks and Unreal Engine 4

are there any limitations to AMD gpu owners in the AndroidWorks pack?
does unreal ensure that both AMD and Nvidia users will receive an equal experience of their engine?
because by the looks of it, the AndroidWorks pack has some features that are for Nvidia Hardware only (PhysX for example).
im asking this because im gonna buy a GPU soon, and unreal is my main tool for development… being “left-out” on is the last thing i’d want (if ill go AMD).

to be honest i wanted to buy an Nvidia GTX970 (i still want), but one thing some things remind me not to:

plus, the whole 3.5GB thingy and no Async Compute… but the Kepler Cripple is the most irritating to me and is quite proven, and Nvidia just ignored it.}