I for one found this chapter almost completely pointless.
Not complaining, Oda has the luxury to make a bad chapter or another since he always delivers great ones. But still, I thought this one felt really stretched with the whole hunt part taking almost a whole chapter and having enough content for just 3 pages. Also, it seems that for a while now Usopp funny scenes fail miserably to get me.
And on a side note, I wonder when Doffy got info about Sabo and Usopp. I supposed he got filled in by Treból and Diamante when Pica got the factory up there but that was, like, 1 minute ago, when Doflamingo was already in the middle of his speech.
Also, it seems like he found out Franky went missing even before his men that were there? Otherwise, what would be the point in giving a bounty to someone his men had already pined down?