There have been multiple instances in the NSMB games where I'll have to exit to the map or just rush to the goal and re-select the stage because I was running low on time while searching or dicking around. It's stupid. The timer is supposedly there to keep you moving along faster, but it has the ironic side effect of wasting your time with situations like this.
I only like it when it's specifically set low to force you to speedrun, because those levels are the only ones that feel like they're designed with a time limit in mind.
Yea, I don't mind those low time levels either.
For me, Super Mario 3D Land is probably the 3D Mario game I played the most (total playtime). I've tried to get the best time in every level beating times of the people I streetpassed. So the timer really is one of my favourite things. Though I wouldn't care even if it wasn't there and there was a timer saying how much time I've used up. It really is the best speedrunning 3D Mario and that adds up lots of replay value to me.