Hi m8s,
You can solve the lag issue by testing for the best IP from below and using it. Maybe some of you are playing quite well and this wont change anything for good but most of you can solve it. It solved for me. Before my latency was something like 300-500 (last couple of days were like a disaster) now its 74-160ms. There are 4 IPs ve found that Aion uses. Here is direct trace links for them. If you're able to find the one which isn't giving any time-outs, than thats the best IP for you.

206.127.147.28: http://network-tools.com/default.asp?prog=trace&host=206.127.147.28
206.127.153.247 http://network-tools.com/default.asp?prog=trace&host=206.127.153.247
206.127.155.130 http://network-tools.com/default.asp?prog=trace&host=206.127.155.130
216.107.250.81 http://network-tools.com/default.asp?prog=trace&host=216.107.250.81

After you found your IP do the following actions:
1. Backup the addcache.xml file from the installation path.
2. Modify the string below with the IP you found.
<Value Regions="EU"> -ip:206.127.147.28-port:2106

Thats it. I hope it can solve your lags if there are
Cya!