There are definite upsides to filibustering the Gorsuch nomination, particularly in the current situation. The downside is frequently exaggerated.
The vote is coming at a time when Trump has lost the ACA/ACHA issue. Resist and the rest of the activists have won, and various Republican groups are in disarray. A senator wants those D activists on his side come election time, and being on their side now is a good first step.
Among the issues with Gorsuch is his dismissal of any rights for workers, and workers were essential to Trump's win. "See? You might have thought that he would help you, but he isn't on your side, and the Democrats still are."
The longer the fight, the more those issues get press.
If the filibuster succeeds, the court is kept from taking an extreme right turn, or returning -- with a much younger man -- to the extremism of Alito.
The downside asserted is that a filibuster would result in the "nuclear option." It would be the last filibuster, and we need the filibuster for later appointments. That assertion has several parts in actuality.
1) What the filibuster is worth. Senate Democrats would differ on the dKos consensus on its worth, but everybody would agree that a filibuster that Democrats can't use is not worth much to Democrats. Back in the late days of the Bush administration, the Senate came to an agreement that:
a) The Republicans would not abolish the filibuster,
b) The Dmocrats would only use it in especially egregious situations.
A few years later, Republicans demonstrated that they would use it in situations which were not egregious at all.
2) The current assertion depends on believing that Republican senators would actually vote in virtual lockstep to abolish the filibuster. Lots of R senators are as committed to the arcana of the Senate as D senators are. (Also, Senate Republicans expressed worries about the bill, and their worries were ignored in favor of the "Freedom Caucus." They’re probably less dedicated to laying down their political careers for Trump than they were last week.)
Democratic women senators lobbied their colleagues to keep the filibuster to protect their right to fight an absolute misogynist off the court; they could lobby the R women senators to keep that protection.
3) It also depends on believing the promise from The Turtle that they won't use this threat on later USSC appointments. This is the man who persuaded Democrats to abstain from calling sessions between the election and the new Congress to push through all of the pending Obama appointments. He did it by promising that Republicans would be less obstructionistic in the new term.
How did that work out?
Altogether, a filibuster is a good idea, and this is the time for it.