mine are not pruned, about 4'-4.5' tall and have been in the garden a long time. they have an open habit but that could be because i am growing them in bright shade.

Mrs GG is literally the same as George Tabor, except of course she's white. They'll get four/five feet tall and an open habit is typical. If you're going to use them for the front foundation, I'd suggest a lower tiered underplating as well to avoid the leggy look.

i would opt for something other than southern indicas as foundation plants unless there is a good bit of height from the ground to windows. 'george l. taber' can get very tall and wide in my area and i personally don't like the sheared look for them. 'mrs. g.g. gerbing' won't likely grow as tall but might get out of range for most foundations, looking too large for a typical one-level home.
some of the kurume azaleas and their hybrids have a tighter growth habit and the small, glossy foliage is more attractive when they are not in flower.

My friend asked for my advice about her foundation plantings, and I told her that Mrs. G.G. Gerbing was a larger azalea which might be too much for the front of her small house; however, her son-in-law insisted on putting five on either side of her front steps. Her house is a one-level craftsman. Boy, is she going to have some major azalea growth. Son-in-law also snuggled in two camellias and two hollies along with the azaleas- a good example of "it looks good when the plants are small, but..." So much for my advice.

According to the tag on the 6 Mrs. G. G. Gerbing Azaleas I purchased from my local nursery, they can reach a height anywhere from no less than 3' with a maximum of 8' tall, they may spread out anywhere from 4' to 6' in width.

So they would make a nice "privacy hedge" that would bloom in the spring. I'm in Florida, which I think is Zone 8-9, but I can't ever remember my actual zone.

They say these only bloom in the Spring, but the ones I have must not know that, as they have also bloomed profusely in both the beginning of the Spring season and then again in early Fall.

I just wish there were a variety like this that could be made to bloom all year round, especially in my area.