The Linksys Cable/DSL Router (4 ports a.k.a. BEFSR41), and the SMC Barricade Cable/DSL Router (4 ports a.k.a. SMC7004BR), are combo appliances.
One part is 4 ports Network Switch with DHCP, and the second part is an Internet Router with a Firewall.
Network Switch Part.
Both have similar functions, and seems to operate well.
Speed: Switches are not the weak part of a small personal, or small office Network. Cables and NIC are the main culprit.
To learn about NIC differences log to this excellent report.
http://www.dslwebserver.com/main/nictest.html
Internet Part:
Speed: This is not an issue, both have 10Mb/sec Wan port, giving that the best of Cable is 4Mb/sec, averaging around 2.5Mb/sec (DSL is less). Internet Speed is not a problem.
The differences come in the firewall, or to be more precise in the capacity to
bypass the firewall.
However, this issue depends on what a person would like to do, there is a large variation in the way people want to use the Internet other then regular surfing.
Issues of VPN connection, FTP server, and ON Line Games, are all involved Firewall bypassing, and have to be studied on an individual basis.
A thorough Review of the Barricade here:
http://www.hardware-one.com/print_review.asp?reviews=211
A thorough Review of the Linksys here:
http://www.practicallynetworked.com/reviews/linksys_router.asp
I am not a Gamer, but it seems that Gamers like the Linksys port mapping better.
The Barricade can be found for $20 less then the Linksys, and it has a Printer Server, and Serial Port for Backup Modem.