Originally Posted by andysalter
I'm aware they are different, maybe I should have stated I am not at all very experienced in this field, and therefore not much idea as to what I would benefit from the most. (Hence why I'm asking on an audiophile forum, to get an expert opinion)
"Benefit" can mean a lot of things, and off the bat we're talking about sound quality, features, and value (price to performance ratio).
Sound quality is hard to judge given we cannot confirm how close it is to the real RA1. Assuming it is close, however, I'd go for the clone amp vs the E10. It also runs off 24v vs just USB 5v for the E10, which can be enough current and power to make a difference in the dynamic range, but then one might have suspicions about the quality of the power supply included with it. You might just have to get a new one down the road - quality ELPACs and other brands can be had for not a lot of money, but you'd need to understand specs properly to make the right choice.
Features, well, there's the reason for the 5v power supply on the E10 - as mentioned it's a DAC-Amp. This one only has a regular USB digital+power input, which basically means that you don't have an analog input - given your sources, a USB digital input might be better since it will probably improve the decoding quality. Do note it isn't sure if the E10 can run off the Xperia Z using USB-OTG, so check the Android DACs thread here first. One of the likely problems is it'll need a USB hub since anything short of a laptop won't be able to put out 5v of power through their USB outputs.
Alternately, you can actually get both instead - the E10 can be used as a DAC, and if you feel that it isn't enough for the AKG, you can get the other amp and hook up the E10's 3.5mm output to its RCA inputs. Better yet, just save your money and buy something like the E17, given it's more proven to sound "right" rather than gamble with $100 or $150 now then rectify it by selling those and blowing $200 again. It's a reality that while there are high-value products, at some point trying to go on the cheap might just cost you more in the long run (or you can come back here foaming at the mouth claiming you can't hear any improvement and people here conned you - it happened quite a few times already).