I know I've said this before, but when I began, I played almost exclusively 3/0 and 3/1 blitz chess for 3 years.
I found 5 minute chess harder... and really any time control longer than the two I mention above was harder for me. It seemed to me players were much slower... but they calculated better than me (like you mention with calculation).
The way I imagined it was like a race car. I had very high acceleration (I could see all the immediate threats and find a safe move much faster than them) but they had a higher top speed... if they were able to think for 10, 20, or 30 seconds then I couldn't see as much as them anymore. My calculation would just kind of go in circles instead of seeing deeper or a variety of moves. This was my impression.
As a online player and specially bullet player , i played like 90% of my blitz in 3 min blitz pool. And for one other reason that everybody knows i am sure and its very common in longer time controls.
I have read players say 3 min is the toughest time control. But for me is not. I find 5 min way more dificult for following reasons:
1. I already mention it above.
2. Since i started to play chess again like 3.5 years ago and blitz for 1.5y ago i find out players with 10-20k blitz games are quite strong really - they have way more experience than me and better calculation habbit (bullet practically kills that) and way better opening preparation (my weakness and basically sometimes i am dead lost after several moves, i like to play many openings but they are already experts at 1-2 lines and since we don't play more than 2-3 games is in their favor)
So i want to hear it from you what do you think...
Is 3min blitz more dificult for you than 5 or 10 min... And how about inc. 3+2 5+5 etc.
I know its a fact that at higher level , title players prefer only 3 min blitz.