Personally I have never lagged in BO3, not once. The only time I've ever had a higher than usual level of latency was playing with friends in the US or Australia (that was fun ) as I'm near London. In Ghosts I would occasionally go through spells of maybe 10 minutes to 3 hours with the odd ping spikes once per month or so where there was blatant congestion on my ISP's end, but I haven't experienced that for months. I play on 5 servers that are all within a 500 mile radius of me, and my ping is either 16ms for the server that's right on my doorstep (it's about 20 miles away, the ping would be around 8ms if BO3's ping reading didn't include processing delays on top of the ping), or 30-34ms for those other 4 servers. I got thrown on to the Polish server once and I had a few games between 50-67ms, but I've never gone beyond 34ms on west EU servers.
(As an aside, isn't it weird how all of these ping values are usually exactly the same as frame lengths? 17ms, 34ms, 50ms, 67ms )
Despite that, BO3 has been the worst game for me in terms of connections so far. I thought BO2 was bad until I got here lol. AW was bad for a reason (I couldn't bring myself to use a god account, so unfortunately I was stuck with maybe the top 5% of players worldwide and rarely ever found games with quality connections. I spent most of my time with folks in Cali, Seattle and Dubai ), and BO3 just doesn't have an excuse. It's not SBMM, it's not PBMM (ping) and it's not RBMM (region), which have all been a part of at least one CoD title over the years. It's just... a terrible game. I've played with more people from Abu Dhabi than the south of England where I live, and I'm pinging a server on my doorstep in under 1 frame.
I don't even want to spend any more time complaining or trying to work it out -- it hurts my head. Maybe 2.5% of all my games in BO3 so far have been on good connections, when my connection is good 100% of the time lmao