I have watched him for a good number of years (a coincidence really), considering I have a girlfriend who is from Dortmund and my cousin supports Club Brugge (I'm from Belgium originally) so I've had the opportunity to see him play many times over the last couple of years. At Club Brugge he was quite the revelation and stood out in that team, however at Dortmund he was very hit and miss and reportedly fell out with Klopp there. Perisic then moved to Wolfsburg and that's where I admittedly stopped following his progress. Therefore my judgement/knowledge on him is limited in that regard.
From my knowledge - I think he is quite a limited player and certainly not the type of player which will have supporters at the edge of their seats but then again, maybe that's not what we need right now. I think with the right manager he might end up being a very solid addition and he clearly brings years of experience with him. However a lot of if's and but's here.
There is the solid argument that we miss a talisman in our final third and to be honest I can tell you already that Perisic is not the player who will transform us. United would be his biggest challenge as of yet, make no mistake there, and with the exception of Club Brugge, he has never transformed a team. I think supporters would have been more happy with this signing if we managed to secure Griezmann along with Perisic, however we failed to do so. I am all for signing Perisic providing we do not pay ridiculous money for him and manage to bring in another player who has the potential to transform our attack.
However, I do have the feeling we will not sign such a player this transfer window and I think supporters are beginning to realise this. That's why some people are venting their frustrations over the Perisic transfer, which is admittedly unfair as he could end up being a very solid addition but far from sufficient considering the state of our current squad and apparent lack of quality up front. I we managed to sign Griezmann (which I believe was the plan); I am guessing there would be a very different tone in this thread.