I’ve been using the Flint 4 for about a week with my 8 Gbps fiber connection. Here are my observations so far.

(+) Observations

(+) Flexible WAN/LAN configuration

There are three different ways you can connect your internet:

• 10 Gbps SFP+ – can be configured as WAN or LAN
• 10 Gbps Ethernet – can be configured as WAN or LAN
• 2.5 Gbps Ethernet – can be configured as WAN or LAN

This gives a lot of flexibility. For example, you can use SFP+ for WAN and 10GbE for LAN, or 10GbE for WAN and SFP+ for LAN.

(+) Very good multi-gig performance

I have an 8 Gbps fiber connection. With Network Acceleration enabled, I’m getting around 6.5 Gbps, which is quite good.

Without Network Acceleration, I get around 4 Gbps.

(+) Good option for a multi-gig/homelab network

The combination of SFP+, 10GbE and 2.5GbE makes the Flint 4 quite flexible if you already have multi-gig switches, servers, NAS or other homelab equipment.

(+) Good DNS and routing flexibility

I’m using my own Pi-hole for DNS and had no problem integrating it with the Flint 4. There are plenty of routing and DNS configuration options compared with a normal ISP router.

(-) Observations

(-) Network Acceleration disables some useful features

This is currently the biggest limitation for me.

When Network Acceleration is enabled, Content Blocking and Data Statistics do not work at all.

So on my connection I basically have to choose between:

Network Acceleration ON → ~6.5 Gbps, but no Content Blocking/Data Statistics

Network Acceleration OFF → ~4 Gbps, Content Blocking/Data Statistics work

For a 1 Gbps connection this probably doesn’t matter, but on a 5–8 Gbps connection the performance difference is significant.

I hope GL.iNet can improve this in future firmware so that at least some of these features can work together with Network Acceleration.

(-) SFP+ does not necessarily replace your ISP ONT

This is something worth knowing before buying the router specifically for its SFP+ port.

If your ISP uses an ONT in their router/device and authentication or optical termination happens there, you cannot simply move the ISP fiber into an SFP+ module on the Flint 4 and expect the connection to work.

In this case, you still need the ISP ONT/router and will need to use bridge mode, then connect it to the Flint 4.

So the SFP+ port is very useful, but whether it can be used directly with your ISP fiber depends on how your ISP provides and authenticates the connection.

Overall

After one week, I’m quite happy with the Flint 4.

The hardware and port flexibility are probably its strongest points for me. Getting around 6.5 Gbps from my 8 Gbps connection is also good.

The biggest issue is currently the trade-off between Network Acceleration and Content Blocking/Data Statistics. If GL.iNet can improve that through firmware, the Flint 4 would be a much better option for people running 5–10 Gbps home networks.