On the Terrace project. First of off all, the tallest building on site is already 100 feet tall with 6 floors according to the architects. Judging from the Terrace's website and the site plan map posted by the American-Statesman, it looks like the two taller buildings would be on the southern end of the site. I would imagine they probably will be prominent in the area and visible from the greenbelt, (the shorter buildings already are). But, they will be setback from the creek. Using GoogleEarth, the nearest new building would be a little over 1,100 feet from the creek.
My brother and I hike there several times a year. We can be there in 5 minutes from our house. I'm also anticipating being able to see them from my neighborhood since when the other buildings were being built I could see the cranes. That will be kind of neat actually.
If the worst part about the project is that you might be able to see it from the creek then I have no problem with it. I'd rather the buildings be taller and reduce the impervious coverage in the area and take up less land, then to have shorter buildings. With less coverage the creek will stay healthier.
Here's a shot I took of the buildings in 2006 at a forum meet in downtown. The new taller buildings would be a little more than twice the height of the building in the middle.