I don't feel like it drags too much. The pace for most of the arc was great, it is just the last two chapters that were worse but it is not bad, I am sure it will be great again in the next few chapters. There is so much going on in this arc, Saturn, Kizaru, Seraphim, Mark 3, Vegapunk(s), traitor, Kuma's flashback, Garp/Law/Boa VS Black, Vivi and Morgans, destruction of Lulucia Kingdom, Kid in Elbaf, etc.
I think the arc will last for more 15~ chapters and we will start the fights in the next 2-3 chapters plus get a big revealtion close to the end of the arc.