My own take on the 'bottom bee-space' vs. 'top bee-space' issue is - it all depends on what you intent to place on top of that box. If it's something hard - like a hard crown-board (inner-cover) or another box, then having a top bee-space helps to prevent the crushing of bees, as well as making the building of crown boards that much simpler - no need then for any spacing battens ...
But - if you're planning on using soft inner covers (only), then the crushing of bees is no longer a major issue, and the soft cover will lie more easily over the top bars when they're more-or-less level with the box top - although I don't think this is uber-essential.
I have been making Long Hives with bee-spaces at both Top and Bottom (the bottom bee-space can be very generous, BTW), but have recently decided to convert over to soft tops for reasons of economy and to simplify manufacture.
All my vertical hives are bottom bee-space (wish they weren't) 'cause that's how they've been commercially manufactured historically, and home-brewing vertical boxes otherwise now, would only cause confusion.
Last year I posted a method of making a Long Hive without plans on a well-known natural beekeeping site, where it was received like the proverbial 'lead balloon', as the use of frames is considered taboo there. I've just uploaded it here as a separate thread, in case there might be one or two ideas there of passing interest ....
LJ