I have recently bought a pressure sensitive Huion 1060pro+ tablet. It's comparable to a medium-level Wacom.
On my Macbook Pro 15" 2009 the pressure sensitivity when working in Illustrator has a rather long lag, sometimes 15 seconds between pressing the pen down harder and the brush stroke becoming thicker. This is the same in both normal brush and blob brush, and Illustrator CC 2013 and CC 2015.
This delay does not happen on Photoshop, or on my girlfriend's Macbook Pro running Illustrator CS6. The hardware on my girlfriend's Macbook is comparable to mine, except for the graphics card - mine has a NVIDIA GeForce 9400M 256 MB, hers has an Intel HD Graphics 4000 1024 MB.
I'm thinking that perhaps my card can't process the changed shape of the vector quickly enough to provide an immediate response.
I'm interested in what you guys think, and if you have any suggestions for improving its performance short of buying a new laptop.