> Still waiting for a PCIe bus as well

RPI3 is not a 'server grade' ARM -

See e.g. the AMD 'Opteron A' boards:

http://www.lenovator.com/product/103.html#params

    CPU Quad-core ARM Cortex-A57 64 bit
	
    DRAM Two DDR3 SO-DIMM sockets
	
    SATA Two SATA ports
	
    USB Two USB 3.0 ports
	
    Console USB-micro port for console support
	
    Ethernet 1 GBe Ethernet
	
    PCIe x16 PCIe G3 slot
	

not sure about the RTC, but the PI is way far from any of the arm 'standardization' efforts, being a low end 'standard' unto itself..