I've had the Keylab 88 for a couple months now and have had several issues. It was so bad that I exchanged the first controller for a new one, thinking there was a defect. Unfortunately the defect seems to be with all of them, as my second controller does all the same irritating stuff.
First, when I'm playing soft piano stuff, all of a sudden I get this random, full velocity note. It's so startling! Doesn't seem to be the same key each time either, but I'm not positive about that because it literally scares me so bad I instinctively pull my hands away. It did it several times this weekend when I was playing at church. It sounds like someone hits one key with a hammer, as hard as they can. It does it with Propellerhead Reason 8, Ableton Live 9 and the standalone versions of PianoTeq and UVi, which were included with the Keylab 88. I'm guessing it's a flaw with the aftertouch, so I used Arturia's MIDIControlCenter to lower the aftertouch velocity to 0.
Secondly, I can't get the transport controls to work with either Reason or Ableton Live. In Reason, if I use the Arturia Keylab 61 controller mapping, the transport will work, but then I have problems with the sustain pedal turning on and it won't turn off. I've tried reversing the polarity of the pedal, tried different pedals and played with the MIDIControlCenter settings...nothing works. If I use a 'generic' control surface mapping, the sustain pedal works as it should, with no polarity issues whatsoever, but then the transport won't work.
Third, when trying to map faders to different instruments in Ableton or Reason, it will only let me use the first two faders, the rest can't be mapped. Same goes for the rotary knobs. I finally had to buy an Akai APC40 controller in order to use the transport, faders and rotary knobs.
This is my first experience with Arturia and quite possibly my last. If I can't come up with a solution in the next few days, I'm going to return the Keylab 88 and buy a quality controller. This is absolutely ridiculous.