I'm the opposite. I like 808 horizontial coil best because I like standard resistance on my VV box. I have a hard time finding standard resistance 510 cartos.
I do use 510 in a few smoketech tanks because the 808 doesn't come in long size (that I've been able to find)
I like the easier draw of the 808. If you like a little tighter draw, you'll like 510 better.
I do, also have the same 510 connection problems 5cardStud has with 510. I have to try 3 or 4 different adapters for each carto to find one that will connect for me, but then I'm set for the day.