Obviously, nothing would be better than to see this issue resolved diplomatically. But I have seen no evidence that Iran is serious about stopping its nuclear weapons program. It looks as though they see these talks as another opportunity to deceive and delay just like North Korea did for years.
They may try to go from meeting to meeting with empty promises. They may agree to something in principle but not implement it. They might even agree to implement something that does not materially derail their nuclear weapons program.
Iran is good at playing this chess game. They know that sometimes you have to sacrifice a pawn to save the king. The goal of these negotiations should be very clear:
Freeze all enrichment inside Iran.
Remove all enriched material outside of Iran.
And dismantle Qom.
When this goal is achieved, I will be the first to applaud. Until then, count me among the skeptics.