Speed testing on a GB internet connection: To VM or not to VM

I am lucky enough to live in an area where i was recently able to upgrade my home internet connection to gigabit fiber.  To date I have been running Sophos UTM as a VM on a Dell R710 I picked up on ebay running ESXi.   Unfortunately that machine was topping out at about 120 Mbits/Second using SpeedTest.net as a benchmark.  For reference, my Dell R710 has dual x5660 2.8 GHz Hexacore CPUs.  I decided since I was paying for the high speed service, I should probably be able to actually use it, so I started looking into a system that I could run UTM and get close to the speed of my internet connection.

The system I picked out is as follows:

Motherboard: GIGABYTE GA-Z170N-WIFI
Processor:  Intel Core i7-6700 8M Skylake Quad-Core 3.4 GHz
Memory:  16GB (2 x 8GB) DDR4 SDRAM 2666  (PC4 21300) 
HardDrive: 128 GB M2 SSD
NIC: Intel PRO/1000 Pt Dual Port PCIe Server Adapter (Intel 82571EB Chip)

Even though the motherboard has 2 Intel NICs on it already, I decided I would use the Server adapter because I had it laying around and there have been reports of issues with the Intel l219 based port.  Sure enough neither ESXi nor Sophos UTM would recognize that port out of the box.

I was really hesitant to dedicate the whole system to running UTM though given the great success I have had with ESXi.  There are only 5 of us using the connection, so a quad core hyperthreading CPU was way overkill.  The only question I had was how much performance I would loose due to the virtualization.  I decided to test it out on 3 configurations.

Config 1: UTM running as a VM under ESXi with 2 virtual NICs each connected to a VM switch attached to its own 82571 port
Config 2: UTM running as a VM under ESXi with both 82571 one ports passed directly through to the VM using DirectPath IO
Config 3: UTM running all by itself on the machine without ESXi

VM Software: ESXi version 6.0 VM version 8 VMs.  Each VM was given 6 processors and 8 GB of RAM on 50 GB partitions

I set UTM 9.401-11 up the same on all 3 configurations with:

As you can see,  all 3 configurations performed very similarly.  The only real difference was upload speed was hindered a bit by using virtual NICs instead of passthrough NICS.  

I have decided to run ESXi on the server and limit UTM to 3 or maybe 4 processors and 6 to 8 GB of ram and give the rest to my PLEX VM