First, I like that this is coming to fruition. Second, I love the extended bolt hole design (no more lost bolts down the frame rail areas or on the headers!).
But I'm going to say loudly, a removable top would be an outstanding idea! Not just clear, for looks, but having a solid aluminum top would be fantastic for quick checking for any excessively loose valve lash, without pulling the entire cover, which requires pulling the tower brace on shock tower cars when combined with this style cover. Having a removable top
as an option is an even better idea, not everyone wants a 'modern' look to their parts, and a solid top still retains that old-school look. I think that's a great call on having both as an option.
But that also leads to the down side of this style; they are not shock tower friendly when changing plugs. I've always found it easier to just remove the entire valve cover when changing plugs, and that's easy to do with the CJ style even with a tower brace. Not so much with these, at least at the rear around the brake reservoir. Just goes to show that you can't kill all the birds with one stone
As for the smaller breather hole, I'm pretty sure we all own funnels, so I don't see that as an issue at all unless 1 1/4" is too small to pull a good vacuum on a vacuum system.