Side door for me, too.
For more than 30 years, I used a Gore-Tex bivy-tent with an end entry. It was 24in/61cm tall in front, 19in/48cm in the middle, and ended in a sock.
With such a low entry, the only way in and out was by rowing on my elbows and heels...notsofun when it was raining and muddy. I addressed that problem in part by making the footprint extra long and rolling it up by the door so I could at least avoid the mud. Still got wet. However, I usually only use a tent for sleeping, spending the rest of my time outside or riding. This one went up in one piece and kept me dry once inside and withstood as much as 4in of unexpected snow one night and wind gusts up to 7-mph/113kmh. Despite its shortcomings -- which I knew when I bought it -- it was a terrific tent for me.
The newer tent is better in some ways.
I can actually sit upright at the hips in my newer 1-man tent. I can change clothes easily inside. The full-length side entry on my current tent is a dream for me. However, it is on the left and many of my older sleeping bags have a zipper on the right and now the tent door is on the left, so when I use those together, I squash the fill out of the bags when entering and exiting. All is well with the left-zip bags. They'll probably go the other way soon. The zipper pulls on all my recent jackets and full-zip jerseys purchased in the last 4 years have changed sides as well.
Side-entry is my favorite feature on the newer tent and one I would really hate to give up.
Best,
Dan.