Due to my previous router not working anymore I was forced into buying a new one and came to the conclusion (after reading several reviews) that the E4200 was a good replacement.
If I'm correct, ever since I got the E4200 I got ping problems while playing online games (Call of Duty, Quake Live etc). My ping is stable mostly (around ~35) and then jumps to 80-100 ping with massive lagspikes for a few seconds. It's really annoying since it prevents to play games properly due to me not being able to hit properly (delay).
Router is on default settings and I've tried to update to the latest firmware for the E4200 which is 1.0.04 - Apparently after doing that my internet got really slow so I decided to downgrade to the first version (1.0.01) which is fine for me, except for the lagspikes.
I don't really know much about these kind of things but a friend of mine told me to ping my router (command prompt) and it showed one difference 't=13' instead of the standard '<1ms'. Also when pinging a different IP (18.104.22.168 Google) I got everything around 14-20 and one big difference which was something like '72'.
When connecting my modem cable (without router attached) no problems occured and everything was stable, so I'm pretty sure it's the E4200 itself.
Hopefully someone knows how to solve this problem (fixing the ping spikes that occur every ~2 minutes or something for a few seconds) otherwise I might be forced to buy a new router once again. Thanks in advance!