I think it depends. Mine made my GMAT experience absolutely horrible.
When I first sat down the pen didn't work at all. I was having to write 12-14 lines to get an 'X.'
I dealt with that as best I could for the 1st couple problems (although not with much luck) and eventually raised my hand, waited 3-4 minutes, and requested a new pen.
I am afraid the new pen was more of the same, and it too didn't want to write.
I contemplated requesting a third, at a cost of 4 minutes, but just gave up. I assumed that if 2 pens could be bad, so could 3, and maybe it was the pad, not the pen.
Overall it was miserable and completely effected my concentration and scoring.
The testing center was in Arizona, and was indifferent to the situation. Not even so much as a 'sorry.'
I had assumed everyone dealt with such a terrible pen but I guess it was just me and the poor other soles that take their GMAT in AZ...