Bought this phone on sale for more ram vs the Compact. Which is also getting Android 6 and is another great phone. Memory doesn't really matter until it does..[photos mostly]. 3 GB's is approaching the max for 32 bit architecture/hardware. [Think (2^^32 =~4GB) vs (2^^64 = alot more) ] which is a hard limit for allocation.
Sony does a tremendous job and is under-appreciated for what they do. Which is make great phones.