If you're running with the ball, those slow defenders catch you for sure, especially if the distance is more than 10-15 meters. Movement on the ball is where they made the biggest changes. Did you use the sliders? I have about 300 hours on FIFA 15 and 16 and the slow CB's catch my fast wingers and strikers all the time when they're moving with the ball (in FIFA 16).
Movement on the ball was slower than pure sprinting on FIFA 15 as well, but not nearly as much, it sometimes feels almost like the rubber band mechanics of racing games where the AI catches you by essentially cheating.

Pace was overpowered in FIFA 15, but underpowered in FIFA 16, according to reports though, they seem to have finally struck the balance in FIFA 17. Agility was also overpowered in FIFA 15, you could make such incredibly fast turns to avoid defenders, this combined with the committed tackling mechanics made defending against pace a real pain, they fixed the latter in 16 though, when you could slide right back up on your feet and continue giving chase if you missed a slide tackle.

Agree 100%.   I actually had a ton of fun playing coop season with a buddy online in Fifa 15.  It was just over the top.  So easy to get those ankle breaking, dilfer dime passes, goals and plays.   We try Fifa 16, but its just sooo slow.  We still got to division 1, albeit far slower, but it is just not as fun as Fifa 15.  

Perhaps I will try PES.   But for sure getting Fifa 17. 

I actually used the sliders on the passing speed in FIFA 16, the passes were horribly slow, I think I had them set to 65 or there abouts. They added the driven pass option in FIFA 16, but this became the go-to option for all passes, even short ones, since regular passes often were simply too weak and got intercepted way too often due to this. In short; the basic pass mechanics were more or less broken in FIFA 16.

@mummelmann no I don't use sliders, I played only one regular online season and around 1000 online games in FUT. Normal passes are good for quick one touch passes, just make sure you don't pass to a marked player. I play a passing game and usually didn't have too much trouble passing my way out of pressure and create chances. I don't think it was broken. Also my defenders don't catch fast wingers or strikers. Just knock the ball forward a bit to gain speed with a striker.

But this is just FUT of course, I know it's a bit more arcade gameplay than H2H.

I've only played 10-12 hours of FUT in both FIFA 15 and 16 combined, so I can't really comment on that mode that much. In career mode, which is where I spend my time, the pace issues and slowed passing is a real issue. There also seems to be major inconsistency in the power bar and what it actually means, sometimes even 2-3 bars can result in a weak pass that gets intercepted, unless one uses the driven pass controls. Driven pass isn't difficult, but forcing me to use a two-button solution as standard passing is a bit silly, which is why I chose to up the slider on passing speed instead.

Perhaps there are some differences between FUT and career mode? I honestly don't know since I have very limited experience with FUT personally.