Seems to be ok and stable. I guess that any similar product from Zyxell
should react similarly

here is how it's configure for me

in the Zywall :

-> I use the SUA only feature for NAT and not full feature
. means M:1 , equal dynamic Nat on a BM38 point if view..
. no static Nat

-> key management IKE

local network subnet range
aaa.bbb.ccc.0 /
-> = remote network in iManager
remote network subnet range
ddd.eee.fff.0 /
-> = local network in iManager

phase 1 main
preshared key (your key)
phase 2 ESP / 3DES / MD5
PFS enabled / DH2

in BM38 :

-> add the Zywall as a member of the S2S service
. public ip address / public mask
. tunnel ip address / tunnel mask
it's a dummy one but mandatory to have the /etc/gateways file
updated to move all the "interesting" packets through the tunnel and
start the negotiation between the 2 devices
. click on non-bordermamaner server
. authentication method pss (preshared key)
. enter the same preshared key than the one defined in the Zywall
. no protected network (had multiple abends with one and didn't try

-> add a third-party rule
. give it a name
. choose the public ip address of the Zywall from the drop-down list
. add a third-party protected network list (aaa.bbb.ccc.0 /
. add a BM protected network list (ddd.eee.fff.0 /
. define action (encrypt, same key life time, 3DES/MD5)

I've a PIX 515 to test also, and a Linksys WRV54G... will post the result