Well, there's also a lot of factors when it comes to things feeling sluggish.

For short periods of time, due to necessity, I've run very simple setups of just the service provider modem, and that could get me to around 10-15ms ping on a DSL line. After all my tweaking, I was running a modem line card (hwic) in my Cisco router, with a firewall and premium wifi. Which dropped response times by upwards of 10ms to ~5ms or so. I've further increased the responsiveness of my connection running a pair of raspberry pi systems which were set up as DNS caching relays using the bind DNS server.

The bandwidth never changed. But it felt a lot faster.

The next point was the firewall that I had in place was set up with QoS to limit the bandwidth of any one system, and manage the fair distribution of the available bandwidth among the devices on the network. This did less for making it feel fast, and was more for making it feel consistent. No matter what was happening on the network, there was always some bandwidth available for whatever else I wanted to do.

Most all in one wifi routers can't do a decent job of QoS, so if someone decides to fire up a download at the full internet bandwidth, everything else slows to a crawl.

I'm kind of an odd case though. I'm a professional Network administrator, and my home network is often better run than my client's networks.

It's downright unusual if I need to restart any of my network equipment to fix a problem. I get frustrated when I have to call my ISP to fix a problem. Usually by the time I call, I already know what the problem is, where it is, and what needs to be done to fix it. So their usual script of restarting the modem and blah blah blah, does exactly nothing, because I've already run through more diagnostics than they even know about. It's a pretty rare case when I can tell them that I have x problem and need y solution, and they'll actually listen. When they do, it saves a lot of time for both them and me. When they refuse to listen, I usually just humor them for about 15 minutes, at which point either they're doing what I want them to, or I'm yelling at them for making my life difficult and asking to speak to a manager. I don't easily suffer fools that think I don't know what I'm doing. I always try to keep my cool because they're just doing their job, and I don't want to make trouble; by the time I'm yelling, it's because they've made trouble for me, or spoken to be like I'm an idiot who can't tell the difference between an ethernet cable and a telephone jack.

I'm way off topic at this point. There's plenty of factors that weigh into whether a connection feels sluggish or not, of which, only one is bandwidth... When you dogpile all your network services into one device, like they do for a wifi router (which is a router, firewall, switch, access point, DHCP server, and frequently DNS relay), it tends to negatively affect its ability to do any of those things well.