I have experience with my 9mm open bolt subgun (MAX-11) and my 9mm closed bolt semi-auto SBR (AR15/9mm) to draw on. Both guns works by straight blow-back, and in both guns the bolt can be adjusted to hit the back of the receiver or not, depending on bolt/buffer, spring and spacer choice.
My open bolt subgun is smoother when the bolt does NOT hit the back of the receiver, and the rate of climb when firing bursts is substantially less. This makes it easier for me to keep the bursts on a target for multiple hits, and makes the burst more controllable when "sweeping" across an array of targets. I suspect a lot of this has to do with the advanced primer ignition feature of the design - the bolt seems to move forwards and backwards in a very predictable and controllable manner. The shooter has to get the timing of recoil recovery perfect to keep the sights dropping back into the middle of the target at the moment of ignition.
My closed bolt SBR is just the opposite - although more abrupt in recoil impulse, a shortened bolt stroke makes the gun feel significantly flatter shooting, with noticeably faster sight recovery, and the speed of splits and transitions is measurably superior. I just posted a thread on this phenomenon, with data,
HERE.
The results could be different with other guns, especially gas operated designs and rifle-calibers with brakes, but the above is my experience with two comparable models, and I hope this answers your question. In any case, the question is moot for civilians - no new open bolt guns for us.