Today I made real contact with the probably worst router that is available on the free market, namely the BinTec X1200 II with IPSec license (yes, you need to license IPSec functionality). The IPSec part is totally broken (more on that later), and the router crashed hard during router configuration, which meant I had to start over two times.
Now the details: my employer currently does a project with another company where we need an IPSec connection. So far, so good. The other side of the IPSec tunnel is some Cisco hardware. So far, so good. Not so good is that our router's (the BinTec thing) IPSec support is totally broken. It took me and a technician from the other company 1.5 hours to get it up and running. The other technician had to work around bugs of the BinTec router, which seems to have problems with a lot of encryption/hash algorithm combinations for ESP, doesn't seem to know about hosts (hosts are always expressed as sub-nets *gna*), and a number of other things I can't remember anymore.
So, people, try not to buy BinTec hardware, if you want to keep off problems, and better invest your money into better things.