I've been recommending NetGear to clients until I discovered a huge
problem that Netgear considers a "Feature".

Netgear SOHO wireless routers (in my case WGR614v7) default to LAN IPs
in the 192.168.1.0/24 netblock. If, however, they detect a packet with
a source IP in this range on the WAN side, they silently and
unilaterally switch the LAN side to 10.0.0.1/24. The reasoning is that
detecting 192.168.1.x on the WAN side means the router WAN port has been
hooked up to such a network, and therefore this subnet cannot be used on
the LAN side. They forgot the possibility that brain-dead DSL providers
might not know enough to configure their modems to filter out such
invalid packets. While this might (barely) make sense for an all-DHCP
home setup, it is incompatible with a SOHO setup where one or more
LAN-attached systems require static IPs. One rogue 192.168.1.x packet
comes in the WAN port and all statically configured systems lose
connectivity. The worst part is that this is not documented anywhere,
and cannot be disabled.

Is this something that all SOHO router manufacturers do? If I tell my
client to buy a different brand, how do I ensure that the same thing
won't happen?