Yeah, I've heard that about UO. You guys should try out The Wrecking Crew. They run ACE and ACRE, and it's a fairly relaxed server. People still attempt to play in squads, and depending on the SL you might be more or less organised, but you'll get teamplay and none of that shouting around feeling terrible for whatever.
I mean, we had this one mission where a guy REALLY like ambulances... so he put his cellphone repeating an ambulance siren and put it on direct comms. Then, OF COURSE, the ambulance gets attacked, we lose a tire, forget medical supplies, men get wounded. Eventually we do enter Zargabad and start clearing out, but this guy finds some excuse to go back for his ambulance, and sure enough, smack in the middle of a hectic firefight, what do we hear? A siren...
Also, the FolkARPS gents run lots of different events, though their website/forum makes it hard to figure them out. Tuesday and Sunday are the "main" unmodded sessions with the most people (had 60+ last Sunday, 30+ Tuesday). Throwback Thursdays is less people and less organisation. Friday is ACE & ACRE, and Saturday is for mods (was Invasion 44, now it's going to be Hell in the Pacific, I think). Also, it doesn't take that long to get missions going. I think they make them so they definitely run under an hour. The downside is there's less "combined operations" with CAS, armour, etc.
I guess my problem is I can't find any friends who actively enjoy this, and then missions to play it, etc. I'd rather join some "pre-made" solution, since I don't really have time for more