Many users experience issues running DisplayLink-attached USB displays with OSX 10.9.x (Mavericks) as well as 10.10 (Yosemite). Because the behavior can be undesirable on many Macs, since the release of Mavericks we have not been recommending our USB graphics devices for use on Mac systems.
All that being said, recently DisplayLink released a beta version of there driver that does offer some improvements. We wrote about it here –> http://plugable.com/2015/03/16/displa…
The key issue here, as I understand it, is the way OS X 10.9+ handles graphics acceleration in some programs. It can result in sluggishness which can be more pronounced when DisplayLink devices are being used. (I’ve found Mission Control to be about the best/worst example of this behavior.)
This is one of the key outstanding issues with DisplayLink on Mac. We can’t say much as far as specific details, but I do know that DisplayLink is trying to improve this behavior with ongoing driver development.