I've been doing a lot of wheel and tire swapping this year and despite all of my previous bitching about Stan's, I've been having very good luck.
The secret? 33mm tape on 30mm inside width rims. I know. I was dubious as well but a guy at corsa convinced me to try it and I'm glad I did.
Basically with the wider tap the sealing is happening at the edges of the tape, where the bead of the tire sits. What this means if you can actually be pretty sloppy when installing it, just stretch it some and make sure the edges are reasonably smooth.
The middle section more directly above the spoke holes doesn't matter since the sealing interface is a sandwich of rim/tape/tire and that bit has a lot of pressure squishing the sandwich together.
I'm like 4 for 4 using Stan's 33 on 30mm rims. I'm still not saying it's great tape but it's easy to get which counts for a lot these days and this approach has been reliable. I still try to stretch it onto the rim with as much tension as I can apply.