About the Roller it doesn't respond at all, even when I'm just listening to a pattern. As you said, it seems to be a bug.
The Roller works except from the latch mode. It work like touch mode in both touch and latch mode.
Again - how do you use the Roller effect?
I've seen then in Spark 2 you can use Pad FX on a single instrument wich is cool. But this means that you can't routes instruments on different tracks and use your own FX (Distortion, Saturation, delay) on every single track, if you want to use Pad Fx as global automation...
The Slicer and the Global filter only work on the instruments routed to the Master out. I can't tell, if this is a bug. In a way it make sense as it is, as i suppose this effects is a audio effets put on the Master out channel. Keep in mind, that you perhaps can use send to the AUX channels from instrument channels set to individual outputs in a creative way here.
The rest of the effects also work on instruments routed to individual output channels. That include the roller as it's midi notes.
Also, it seems impossible to records filters and slicers in a pattern. Any thoughts?
I think the answer is in the name "FX Live pad and Effect buttons". It can't be recorded in the patterns. It's a live feature.
But keep in mind that you do have some automation parameters you can add and use in the Sequencer view. And you can record the FX Live pad automation in a DAW.
however I'm still experiencing bizarre behaviors with this pad. Filters works fine and I can record the automation in Reaper (in live). On the other hand, Slicer work when I record a track and the automation is there, but the midi does not respond to the automation (see image attached).
That perhaps can be because you start the playing to close to the effect.
Please keep in mind, that i'm not using Reaper.
I've noticed that now I can't drag patterns in a Reaper track as Spark Creative (I think that Arturia disabled this because of Logic users that where experiencing crash).
I have the feature and can do this, if you mean when selecting the Spark Creative GUI in the preferences and use that GUI, and then drag a pattern to a DAW.