Is puzzle rush a good way to improve?

I think it would be Good for pattern recognition.

All highly ranked chess players are quite good at identifying tactical opportunities and threats. I am confident that there are no GMs who can only score 15 or 20 on Puzzle Rush. Strong tactical ability alone won't make someone a good chess player, but it is a requirement to be a good chess player because you can't defend against potential tactics you can't identify.

Whether you prefer to practice enhancing your tactical skills via Puzzle Rush, Tactics Trainer, or some other way depends on what you like and what works best for you.  jmho

This is exactly what I started thinking after a week of puzzle rush.  So much time spent on easy tactics to then fail on the motifs that need work.

Here is my experience. For about 2 months I had the daily routine of doing one puzzle rush, one puzzle duel, a few tactics puzzles and a blitz game. I did not improve on the puzzle rush but my blitz rating after an initial increase to about 1700 decreased to around 1550, losing a lot of games due to impulsive one move blunders. In the meantime, I switched to solving around 15 easy tactical puzzles daily (basically 2- to 3-movers without any time limit), which seems to help to increase my puzzle rush performance.

I think rush is good to speed up thinking for Blitz and it can highlight problem areas in your tactical thinking.

I guess a combination of puzzle rush and normal puzzles would be best tactically, improve on your deep calculation whilst improving intuition and immediate pattern recognition.