Thanks for the posts, maybe I should have phrased it better.

I hear what you say about neck resets however there are different flavors of Spanish heel including those that include wedges in the design, it is this type of information that I am looking for.

Regards

John

Whether the neck is integral or bolted on or dovetailed or whatever, doesn't affect how you need to manage your angles to achieve your target string height above the soundboard. One thing I like about integral is that, if you use a headblock extension to the upper transverse brace, it guarantees the fingerboard and upper bout surfaces are coplanar, thus no dropoff or ski-jump after the 14th fret. But if you normally use a 1.5 degree neck angle or whatever, then you need to make sure that upper bout surface is at a 1.5 degree angle to the sides, by some means or another (careful arching of the upper transverse brace, for instance).

Depending on your fingerboard thickness and soundboard arching (or lack thereof) and target string height at bridge, you may or may not need an angle... In Ervin Somogyi's book, he says he goes for 0 angle between the neck surface and bridge spot on the soundboard. i.e. the fingerboard thickness plus fret height plus slight upward angle of strings for proper action minus slight pulling up of the top under tension all work out to his target string height.

Another technique you can use to control the angle is tapering of the fingerboard thickness. If you make it 1/16" thinner at the nut end than at the 12th fret, then the projected string height at the bridge will be 1/16" higher.

Resets are certainly an issue though. I'm not a believer that resets are inevitable (well, they probably are if all you put in your upper bout is a popsicle brace... ), but I'm also wary of building more integral necks just yet, as I am a fan of thin tops and light bracing, and am still learning what is "too flexible" My last one pulled up about 1/8" in the first few days, but fortunately I got the neck angle a fair bit higher than intended, so that actually worked out just about perfectly

I don't think the ski jump or drop-off or whatever at the body has anything to do with the structural choices made in terms of upper bout support - the change in angle of the fretboard at the body is dependent on getting the right geometry built into the upper bout and then setting the appropriate neck angle.

Whether the upper bout distorts over time and causes a rising extension is a different issue, and I've seen more issues with collapsing upper bouts due to rotating neck block extensions than I have any issues with guitars that use standard blocks without additional support (the popsicle is an anti-shear device, and plays no role in preventing/controlling neck block rotation).

…but once the neck block begins to rotate, a rigid extension can load the UTB.

There is a long standing debate among classical makers as to whether the separate dovetail or mortoise and tenon neck joints are less rigid than those built in the Spanish style.
I've never tested this, but I can say that the Spanish construction is extremely rigid.

I think the concept could indeed be successful with steel strings given the right modifications.

John's point about neck rotation in traditional steel strings is well taken, but that may be reflective of the deficiencies present in the traditional dovetail construction.
Something that even Martin has moved well away from with the footed neck blocks that they are now using.