I realized that I have not responded to the OP's original request for suggestions in the less than $800 range. Unfortunately, the Sierra 2 will be over your budget, and I have no opinion on the others as I have not heard them.
Given my experience with the NRT Sierra 1s, however, I would seriously consider paying the premium for the 2s when they become available in November. These things will undoubtedly be among the very best two way bookshelf speakers available at any price. Since no one other than the manufacturer has as of yet heard them, I can't tell you how they sound. Going by the design goals posted by the manufacturer, they will be accurate, have a great polar response top to bottom, and exhibit great detail, and dynamics. That sounds just like my Sierra-1 NRTs, only these will be even better both on the high end with the RAALs, and the mid range frequencies are said to also have been improved.
In an effort to provide full disclosure, I was so impressed with the Sierras, that I now have a full complement of 4 Sierra Towers, a Horizon center (all with the RAAL tweeters) and the NRT Sierras are now doing duty as rears in my 7.1 system. Mere words cannot even describe!
Heavily addicted SACDBA member, starting the twelve steps tomorrow!