All SOHO switches are cheap, as in terrible. That's why they're so cheap.
You don't really expect for a $200 24-port switch to be as fast or as reliable as a $3000 24-port switch, based solely on the fact that it's unmanaged, do you?
You get what you pay for.
That said, a Cisco 2911 and a SM-ES3G-24-P will get you a great router/firewall/switch. You're not going to like the price, though.
Also, most fixed-configuration L3 switches (such as a 3750 or an EX2200) do not support NAT and thus are not useful in this instance.
Hmmm, funny, not my experience.
As fast as a $3000 24-port switch, ABSOLUTELY! Why wouldn't it be? If the switching fabric can handle full port speed at full duplex for all ports, it'll be EXACTLY as fast as a $3000 24-port switch and if matters, I've tested dozens of switches (both cheap dumb switches, good semi-managed L2 switches, fully managed L2 switches and L3 switches, both ones I've owned, borrowed as well as worked with) and I've never noticed a difference in networking performance at the same packet size other than standard test variation between tests (IE less than a 1% difference from test to test and across switches). There are of course differences in features, such as supporting jumbo frames, VLANs, etc. I have also seen issues such as claiming jumbo frame support, but not actually working, etc. Feature bugs (but I've seen them in $2,000 L3 switches and in $20 dumb switches).
As relaible, hmmm, maybe not. I've yet to have a switch die or cause real problems (other than one of my semi-managed L2s, which hiccuped when I had a power surge that fried my ONT box, that required a factory reset on the switch and its been working fine since). Granted I HAVE seen problem switch, I've just never owned one. I am probably on switch number....30? At this point over the years.
I can't think of a time I've bought "an expensive" switch. Mostly dumb or semi-managed L2 switches (back in the day, 10Mbps, then 10/100 and now gigabit switches).