I didn't feel overly let down with any pokemon really. The six pokemon I set my sights on (Samurott, Conkeldurr, Reuniclus, Cohagrigus, Scolipede and Darmanitan) did quite well for me. I was let down that Cohagrigus wasn't a Ghost/Steel type though....but I got over it.
I would say the Monkey trio feel very underwhelming to me, to the point where I would never consider them for my team at all. I really love a lot of the Unova pokemon designs but I'm not overly fond of the Monkey trio evolutions....they kind of also feel like they need a second evolution too. They don't look very tough/capable.