There are a couple of mistakes in there.
The reload and refresh methods do not require arguments.
You should suppress the Booleans returned from entering in your CSV by redirecting the result to Out-Null
The firewall list method only has a Name and Enabled property in the returned object.

Get-VMHost -PipelineVariable esx |
ForEach-Object -Process {
        $sLog = @{
            loghost = 'tcp://server.com:1514'
        }
        $esxcli = Get-EsxCli -VMHost $esx -V2
        $old = $esxcli.system.syslog.config.get.Invoke()
        $old2 = $esxcli.network.firewall.ruleset.list.Invoke(@{rulesetid = 'syslog' })
        if ($esxcli.system.syslog.config.set.Invoke($sLog)) {
            $esxcli.system.syslog.reload.Invoke() | Out-Null
            if ($esxcli.network.firewall.ruleset.set.Invoke(@{rulesetid = 'syslog'; enabled = $true })){
                $esxcli.network.firewall.refresh.Invoke() | Out-Null
                New-Object -TypeName PSObject -Property ([ordered]@{
                        vCenter            = ([uri]$esx.ExtensionData.Client.ServiceUrl).Host
                        VMHost             = $esx.Name
                        SyslogOld          = $old.RemoteHost
                        SyslogNew          = $esxcli.system.syslog.config.get.Invoke().RemoteHost
                        FirewallRulesetOld =  $old2.Enabled
                        FirewallRulesetNew = $esxcli.network.firewall.ruleset.list.Invoke(@{rulesetid = 'syslog' }).Enabled
                    })
            }
        }
    else {
        Write-Error "Syslog configuration failed on $($esx.Name)"
    }
} | Export-Csv -Path "c:\file.csv" -NoTypeInformation -UseCulture