It hasn't changed overall. Some RMs are plain bad (internet quality, emulators), some RMs are "great" despite OB's not-so-good netcode.
Example of good, despite being the DT siege, the naturally laggiest situation in Outbreak:
https://www.twitch.tv/videos/574941857?t=0h24m00s - If you've played DT online, you know how bad it is by default. RM was wictorious. Also, ignore the freeze at the end, DT does that often.
I'll try to keep this thread in mind, as there are a dozen or more players I could name with borderline unplayable RM lag NOT caused by distance.
What makes any complaints so hard to diagnose is that there are many factors that can result in tremendous lag or even a pause in activity like the videos linked here. Most of your experience on non-RM is going to come down to the RM. Right at the source, you're depending on them having a decent setup to emulate, and even then, you're hoping that there isn't something eating up their cpu in the background. From there, you're dependent on their connection - if they're using unreliable wifi, you could very well end up with a situation where there's a break in transmission, even for a short time, which can result in a ton of retransmitted packets arriving all at once, and you get the situation where you receive a rush of enemy position, other player position, and attack data all in a few seconds. Something important to note is that Outbreak uses TCP, which means that every single packet that's sent needs to be received on the other end. Any packets that aren't received need to be retransmitted, which can compound the problem. Another point is that each and every packet needs to go to the server before it goes to the players. There is no direct communication between any player, so if you've got two people that are each far from the server, you're actually doubling the ping time or more. It's not how far you are from your co-op friends - it's how far they are from the server, and *add* how far you are from the server to that equation.
Even if your room master has a stellar connection and good hardware, if you're playing with someone that's relatively far away from either you or the server, there are tons of nodes between their location and the server, and any of those nodes could be a failure or lag point, which will also end up in delays and retransmissions. This is largely out of control of the user and not even in the control of their ISP. It's just a fact of internet infrastructure. These issues can even be sporadic, so you can have a situation where 90% of their packets timely arrive at the server, but problems in between the RM and server can manifest and then disappear quickly and seemingly at random. If some of their packets arrive in 13 ms, but others arrive at 120ms, and then 200ms, and then back down to 50ms, that's called "jitter" and it's a problem that's not going to be obvious in many other internet usage applications like browsing.
Assuming the room master's packets have reached the server with no inordinate delay, the server might be short on CPU or having internet issues of its own. We've recently removed the old shoutbox and there should not be any cpu usage issues here. I've also pinged the server from my address and let the command run for a while - I saw very consistent round trip ping times, without jitter, and with rare instances of packet drops with 82 users logged into the lobby or in-game.
So let's say that your RM has good hardware, a good connection, and gets their info to the server on time. Well, all the issues that could've arisen between the RM and the server can occur at any point in the internet infrastructure between the server and you. And your client (the game) needs to send acknowledgement packets back to the server. And your wifi could have intermittent jitter. Or dropouts. Or the connection between your house and your default gateway (the first node at the IP), could be inconsistent for reasons that are outside of your control.
So when we get reports that there are times that lag gets terrible, it's really difficult to diagnose. Especially since the game server is so minimal. It has one job: take packets from each player, and simply send them out to the other players. It doesn't track any variable that goes on in the game, it doesn't even do game setup. It is, from a design perspective, "dumb."
Maybe as a start, if you're having consistent lag issues, try pulling up a cmd window if you're in windows, and use the command "ping -t obsrv.org" and open another one with "ping -t google.com". Let these commands run while you play. If you run into a situation where suddenly players stop updating, or something similar, take a look at the obsrv window first, noting the time. If the time in ms is suddenly very high, or you're seeing "request timed out," there's something going on between you and the server. We don't know what, and we don't know whose end the "fault" is closer to, but it's at least a start. At the same time, if you see the google ping window doing something similar, it means that most likely your or your ISP is having issues. It's a good idea to look at the ping times generally, and if they're consistently on the lower side, and you don't see much variance, then there's nothing more you can do. If things are acting up in game and you see that the ping time has remained consistent and there are not dropped packets, it means the problem is elsewhere, and it's almost certainly another players' emulator, or their connection. This is all good info to have.