I used to punch everything, mostly out of convience (key ring attachement type), for my preference of a more restricted draw rather than open draw. Once punched, I had the option of going straight (guillotine) cut or adding more punches.

Now I just straight cut everything, mostly because I lost my punch and have forgotten (until now) about it.

For nicotine build-up, taste, strength and anything else- I don't recall anything noticeable between a straight and a punch. It was always a draw or cut preference for me. I think punches are good for ~50 gauges and under, but a single punch wouldn't be ideal above that.