Some users have recently had their accounts hijacked. It seems that the now defunct EVGA forums might have compromised your password there and seems many are using the same PW here. We would suggest you UPDATE YOUR PASSWORD and TURN ON 2FA for your account here to further secure it. None of the compromised accounts had 2FA turned on.
Once you have enabled 2FA, your account will be updated soon to show a badge, letting other members know that you use 2FA to protect your account. This should be beneficial for everyone that uses FSFT.
I would say the E4 are worth the $40 difference. Heck I think they're worth $100 difference since that's what I paid when I was in Tokyo and found my E5 had lost the right channel somewhere over the Pacific. But if you can swing the extra $150 or so and you want solid, heavy bass in your IEMs, get the E5. Unless you want to spend $500+ for the professional IEMs, nothing beats the bass of the E5 in my opinion.
Edit: Though I have read that the UM2 has the same bass as the E5 with a more balanced sound, I have not had the opportunity to try them yet. Chalk it up to the lateness of the original post to my forgetting about the UM2.