I have tested both G5 and E5
E5 uses SBX pro and G5 uses BlasterX Acoustic Engine, based on my testing it is just different name for both.. they use same HW and therefore surround sounds the same, literally absolutely the same. Creative just used different software name it seems. (And I SUSPECT that x7 is the very same surround, as based on videos and screenshots it has the same slider and pointer at 67% as E5.)
E5 has Crystal voice function but if you turn it off you get microphone noise (Antlion ModMic 4)
G5 does not have this function in software but it seems enabled by default, there is no mic noise whatsoever, so microphone noise suppression seems to be on by default and I did not find a way on how to turn it off.
Basically after all, the ONLY real difference between E5 and G5 is battery and bluetooth support in E5 and the price is NOT worth it for a PC gamer.
Also E5 USB is not acting like a HUB for PC so you cannot connect for example wireless transmitted for your mouse in to this port (I have my g403 wireless transmitter in my G5 and it works awesome)
The surround itself seem to be working fine at 67% and I personally think it is personal preference whether you like old SBX or new SBX/BXAE.
Also.. old SBX devices all have high output impedance and only G5/E5 have 2.2 ohm which is great for sensitive headphones like HD558/HD598
For comparison, SB omni has 15 ohm OI, SB Z has 22 ohm OI, for best headphone performance you need to have lower OI than impedance of your headphones so HD558/HD598 work flawless on 6.5ohm and less output impedance.
To me personally, playing Playerunknown's Battlegrounds.. G5 is very accurate with 7.1 surround sound and with EQ changes to lower highs a bit (basically change eq to my preference and headphones signature) I have absolutely no issues with it. I will keep it and return the E5 tommorow.