iRule to load balance by browser type

You can simply combine the two. This is an incomplete example, but should get you heading where you need:

when HTTP_REQUEST {
    if { [HTTP::uri] eq "/"} {
        switch -glob [HTTP::header value "User-Agent"] {
            "*MSIE 6*" -
            "*MSIE 7*" -
            "*MSIE 8*" {
                HTTP::redirect "http://larrymoecurly.mysite.com/wfc/loginIEHere"
            }
            default {
                HTTP::redirect "http://larrymoecurly.mysite.com/wfc/login"
            }
        }
    }
}

It would be possibly fruitful to read this article:

• https://developer.mozilla.org/en-US/docs/Browser_detection_using_the_user_agent

If it's possible, it may be more robust to have the client use Javascript to determine the version then insert that information in the request, in a header, or in a Cookie. This may be more reliable (and flexible) than using the User-Agent string.

Finally, if you are using at least 11.4.0, you can likely achieve what you want by using Local Traffic Policies:

• SOL15085: Overview of the Local Traffic Policies feature